1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization.
29 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
30 and to process initializations in declarations (since they work
31 like a strange sort of assignment). */
35 #include "coretypes.h"
45 #include "diagnostic.h"
49 static tree convert_for_assignment (tree, tree, const char *, tree, int);
50 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
51 static tree rationalize_conditional_expr (enum tree_code, tree);
52 static int comp_ptr_ttypes_real (tree, tree, int);
53 static int comp_ptr_ttypes_const (tree, tree);
54 static bool comp_except_types (tree, tree, bool);
55 static bool comp_array_types (tree, tree, bool);
56 static tree common_base_type (tree, tree);
57 static tree lookup_anon_field (tree, tree);
58 static tree pointer_diff (tree, tree, tree);
59 static tree get_delta_difference (tree, tree, int);
60 static void casts_away_constness_r (tree *, tree *);
61 static bool casts_away_constness (tree, tree);
62 static void maybe_warn_about_returning_address_of_local (tree);
63 static tree lookup_destructor (tree, tree, tree);
65 /* Return the target type of TYPE, which means return T for:
66 T*, T&, T[], T (...), and otherwise, just T. */
69 target_type (tree type)
71 type = non_reference (type);
72 while (TREE_CODE (type) == POINTER_TYPE
73 || TREE_CODE (type) == ARRAY_TYPE
74 || TREE_CODE (type) == FUNCTION_TYPE
75 || TREE_CODE (type) == METHOD_TYPE
76 || TYPE_PTRMEM_P (type))
77 type = TREE_TYPE (type);
81 /* Do `exp = require_complete_type (exp);' to make sure exp
82 does not have an incomplete type. (That includes void types.)
83 Returns the error_mark_node if the VALUE does not have
84 complete type when this function returns. */
87 require_complete_type (tree value)
91 if (processing_template_decl || value == error_mark_node)
94 if (TREE_CODE (value) == OVERLOAD)
95 type = unknown_type_node;
97 type = TREE_TYPE (value);
99 /* First, detect a valid value with a complete type. */
100 if (COMPLETE_TYPE_P (type))
103 if (complete_type_or_else (type, value))
106 return error_mark_node;
109 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
110 a template instantiation, do the instantiation. Returns TYPE,
111 whether or not it could be completed, unless something goes
112 horribly wrong, in which case the error_mark_node is returned. */
115 complete_type (tree type)
117 if (type == NULL_TREE)
118 /* Rather than crash, we return something sure to cause an error
120 return error_mark_node;
122 if (type == error_mark_node || COMPLETE_TYPE_P (type))
124 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
126 tree t = complete_type (TREE_TYPE (type));
127 if (COMPLETE_TYPE_P (t) && ! processing_template_decl)
129 TYPE_NEEDS_CONSTRUCTING (type)
130 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
131 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
132 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
134 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
135 instantiate_class_template (TYPE_MAIN_VARIANT (type));
140 /* Like complete_type, but issue an error if the TYPE cannot be completed.
141 VALUE is used for informative diagnostics. DIAG_TYPE indicates the type
142 of diagnostic: 0 for an error, 1 for a warning, 2 for a pedwarn.
143 Returns NULL_TREE if the type cannot be made complete. */
146 complete_type_or_diagnostic (tree type, tree value, int diag_type)
148 type = complete_type (type);
149 if (type == error_mark_node)
150 /* We already issued an error. */
152 else if (!COMPLETE_TYPE_P (type))
154 cxx_incomplete_type_diagnostic (value, type, diag_type);
161 /* Return truthvalue of whether type of EXP is instantiated. */
164 type_unknown_p (tree exp)
166 return (TREE_CODE (exp) == OVERLOAD
167 || TREE_CODE (exp) == TREE_LIST
168 || TREE_TYPE (exp) == unknown_type_node);
172 /* Return the common type of two parameter lists.
173 We assume that comptypes has already been done and returned 1;
174 if that isn't so, this may crash.
176 As an optimization, free the space we allocate if the parameter
177 lists are already common. */
180 commonparms (tree p1, tree p2)
182 tree oldargs = p1, newargs, n;
186 len = list_length (p1);
187 newargs = tree_last (p1);
189 if (newargs == void_list_node)
198 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
203 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
205 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
207 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
210 else if (! TREE_PURPOSE (p1))
212 if (TREE_PURPOSE (p2))
214 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
220 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
222 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
224 if (TREE_VALUE (p1) != TREE_VALUE (p2))
227 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
230 TREE_VALUE (n) = TREE_VALUE (p1);
238 /* Given a type, perhaps copied for a typedef,
239 find the "original" version of it. */
241 original_type (tree t)
243 while (TYPE_NAME (t) != NULL_TREE)
245 tree x = TYPE_NAME (t);
246 if (TREE_CODE (x) != TYPE_DECL)
248 x = DECL_ORIGINAL_TYPE (x);
256 /* T1 and T2 are arithmetic or enumeration types. Return the type
257 that will result from the "usual arithmetic conversions" on T1 and
258 T2 as described in [expr]. */
261 type_after_usual_arithmetic_conversions (tree t1, tree t2)
263 enum tree_code code1 = TREE_CODE (t1);
264 enum tree_code code2 = TREE_CODE (t2);
267 /* FIXME: Attributes. */
268 my_friendly_assert (ARITHMETIC_TYPE_P (t1)
269 || TREE_CODE (t1) == COMPLEX_TYPE
270 || TREE_CODE (t1) == ENUMERAL_TYPE,
272 my_friendly_assert (ARITHMETIC_TYPE_P (t2)
273 || TREE_CODE (t2) == COMPLEX_TYPE
274 || TREE_CODE (t2) == ENUMERAL_TYPE,
277 /* In what follows, we slightly generalize the rules given in [expr] so
278 as to deal with `long long' and `complex'. First, merge the
280 attributes = (*targetm.merge_type_attributes) (t1, t2);
282 /* If one type is complex, form the common type of the non-complex
283 components, then make that complex. Use T1 or T2 if it is the
285 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
287 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
288 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
290 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
292 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
293 return build_type_attribute_variant (t1, attributes);
294 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
295 return build_type_attribute_variant (t2, attributes);
297 return build_type_attribute_variant (build_complex_type (subtype),
301 /* If only one is real, use it as the result. */
302 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
303 return build_type_attribute_variant (t1, attributes);
304 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
305 return build_type_attribute_variant (t2, attributes);
307 /* Perform the integral promotions. */
308 if (code1 != REAL_TYPE)
310 t1 = type_promotes_to (t1);
311 t2 = type_promotes_to (t2);
314 /* Both real or both integers; use the one with greater precision. */
315 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
316 return build_type_attribute_variant (t1, attributes);
317 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
318 return build_type_attribute_variant (t2, attributes);
320 /* The types are the same; no need to do anything fancy. */
321 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
322 return build_type_attribute_variant (t1, attributes);
324 if (code1 != REAL_TYPE)
326 /* If one is a sizetype, use it so size_binop doesn't blow up. */
327 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
328 return build_type_attribute_variant (t1, attributes);
329 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
330 return build_type_attribute_variant (t2, attributes);
332 /* If one is unsigned long long, then convert the other to unsigned
334 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
335 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
336 return build_type_attribute_variant (long_long_unsigned_type_node,
338 /* If one is a long long, and the other is an unsigned long, and
339 long long can represent all the values of an unsigned long, then
340 convert to a long long. Otherwise, convert to an unsigned long
341 long. Otherwise, if either operand is long long, convert the
344 Since we're here, we know the TYPE_PRECISION is the same;
345 therefore converting to long long cannot represent all the values
346 of an unsigned long, so we choose unsigned long long in that
348 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
349 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
351 tree t = ((TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
352 ? long_long_unsigned_type_node
353 : long_long_integer_type_node);
354 return build_type_attribute_variant (t, attributes);
357 /* Go through the same procedure, but for longs. */
358 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
359 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
360 return build_type_attribute_variant (long_unsigned_type_node,
362 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
363 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
365 tree t = ((TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
366 ? long_unsigned_type_node : long_integer_type_node);
367 return build_type_attribute_variant (t, attributes);
369 /* Otherwise prefer the unsigned one. */
370 if (TREE_UNSIGNED (t1))
371 return build_type_attribute_variant (t1, attributes);
373 return build_type_attribute_variant (t2, attributes);
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
379 return build_type_attribute_variant (long_double_type_node,
381 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
382 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
383 return build_type_attribute_variant (double_type_node,
385 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
386 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
387 return build_type_attribute_variant (float_type_node,
390 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
391 the standard C++ floating-point types. Logic earlier in this
392 function has already eliminated the possibility that
393 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
394 compelling reason to choose one or the other. */
395 return build_type_attribute_variant (t1, attributes);
399 /* Subroutine of composite_pointer_type to implement the recursive
400 case. See that function for documentation fo the parameters. */
403 composite_pointer_type_r (tree t1, tree t2, const char* location)
410 /* Determine the types pointed to by T1 and T2. */
411 if (TREE_CODE (t1) == POINTER_TYPE)
413 pointee1 = TREE_TYPE (t1);
414 pointee2 = TREE_TYPE (t2);
418 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
419 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
424 Otherwise, the composite pointer type is a pointer type
425 similar (_conv.qual_) to the type of one of the operands,
426 with a cv-qualification signature (_conv.qual_) that is the
427 union of the cv-qualification signatures of the operand
429 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
430 result_type = pointee1;
431 else if ((TREE_CODE (pointee1) == POINTER_TYPE
432 && TREE_CODE (pointee2) == POINTER_TYPE)
433 || (TYPE_PTR_TO_MEMBER_P (pointee1)
434 && TYPE_PTR_TO_MEMBER_P (pointee2)))
435 result_type = composite_pointer_type_r (pointee1, pointee2, location);
438 pedwarn ("%s between distinct pointer types `%T' and `%T' "
441 result_type = void_type_node;
443 result_type = cp_build_qualified_type (result_type,
444 (cp_type_quals (pointee1)
445 | cp_type_quals (pointee2)));
446 result_type = build_pointer_type (result_type);
447 /* If the original types were pointers to members, so is the
449 if (TYPE_PTR_TO_MEMBER_P (t1))
451 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
452 TYPE_PTRMEM_CLASS_TYPE (t2)))
453 pedwarn ("%s between distinct pointer types `%T' and `%T' "
456 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
460 /* Merge the attributes. */
461 attributes = (*targetm.merge_type_attributes) (t1, t2);
462 return build_type_attribute_variant (result_type, attributes);
465 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
466 ARG1 and ARG2 are the values with those types. The LOCATION is a
467 string describing the current location, in case an error occurs.
469 This routine also implements the computation of a common type for
470 pointers-to-members as per [expr.eq]. */
473 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
474 const char* location)
481 If one operand is a null pointer constant, the composite pointer
482 type is the type of the other operand. */
483 if (null_ptr_cst_p (arg1))
485 if (null_ptr_cst_p (arg2))
492 If one of the operands has type "pointer to cv1 void*", then
493 the other has type "pointer to cv2T", and the composite pointer
494 type is "pointer to cv12 void", where cv12 is the union of cv1
497 If either type is a pointer to void, make sure it is T1. */
498 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
506 /* Now, if T1 is a pointer to void, merge the qualifiers. */
507 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
512 if (pedantic && TYPE_PTRFN_P (t2))
513 pedwarn ("ISO C++ forbids %s between pointer of type `void *' and pointer-to-function", location);
515 = cp_build_qualified_type (void_type_node,
516 (cp_type_quals (TREE_TYPE (t1))
517 | cp_type_quals (TREE_TYPE (t2))));
518 result_type = build_pointer_type (result_type);
519 /* Merge the attributes. */
520 attributes = (*targetm.merge_type_attributes) (t1, t2);
521 return build_type_attribute_variant (result_type, attributes);
524 /* [expr.eq] permits the application of a pointer conversion to
525 bring the pointers to a common type. */
526 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
527 && CLASS_TYPE_P (TREE_TYPE (t1))
528 && CLASS_TYPE_P (TREE_TYPE (t2))
529 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
532 class1 = TREE_TYPE (t1);
533 class2 = TREE_TYPE (t2);
535 if (DERIVED_FROM_P (class1, class2))
536 t2 = (build_pointer_type
537 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
538 else if (DERIVED_FROM_P (class2, class1))
539 t1 = (build_pointer_type
540 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
543 error ("%s between distinct pointer types `%T' and `%T' "
544 "lacks a cast", location, t1, t2);
545 return error_mark_node;
548 /* [expr.eq] permits the application of a pointer-to-member
549 conversion to change the class type of one of the types. */
550 else if (TYPE_PTR_TO_MEMBER_P (t1)
551 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
552 TYPE_PTRMEM_CLASS_TYPE (t2)))
554 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
555 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
557 if (DERIVED_FROM_P (class1, class2))
558 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
559 else if (DERIVED_FROM_P (class2, class1))
560 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
563 error ("%s between distinct pointer-to-member types `%T' and `%T' "
564 "lacks a cast", location, t1, t2);
565 return error_mark_node;
569 return composite_pointer_type_r (t1, t2, location);
572 /* Return the merged type of two types.
573 We assume that comptypes has already been done and returned 1;
574 if that isn't so, this may crash.
576 This just combines attributes and default arguments; any other
577 differences would cause the two types to compare unalike. */
580 merge_types (tree t1, tree t2)
582 enum tree_code code1;
583 enum tree_code code2;
586 /* Save time if the two types are the same. */
589 if (original_type (t1) == original_type (t2))
592 /* If one type is nonsense, use the other. */
593 if (t1 == error_mark_node)
595 if (t2 == error_mark_node)
598 /* Merge the attributes. */
599 attributes = (*targetm.merge_type_attributes) (t1, t2);
601 if (TYPE_PTRMEMFUNC_P (t1))
602 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
603 if (TYPE_PTRMEMFUNC_P (t2))
604 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
606 code1 = TREE_CODE (t1);
607 code2 = TREE_CODE (t2);
613 /* For two pointers, do this recursively on the target type. */
615 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
616 int quals = cp_type_quals (t1);
618 if (code1 == POINTER_TYPE)
619 t1 = build_pointer_type (target);
621 t1 = build_reference_type (target);
622 t1 = build_type_attribute_variant (t1, attributes);
623 t1 = cp_build_qualified_type (t1, quals);
625 if (TREE_CODE (target) == METHOD_TYPE)
626 t1 = build_ptrmemfunc_type (t1);
635 quals = cp_type_quals (t1);
636 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
637 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
638 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
640 t1 = cp_build_qualified_type (t1, quals);
646 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
647 /* Save space: see if the result is identical to one of the args. */
648 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
649 return build_type_attribute_variant (t1, attributes);
650 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
651 return build_type_attribute_variant (t2, attributes);
652 /* Merge the element types, and have a size if either arg has one. */
653 t1 = build_cplus_array_type
654 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
659 /* Function types: prefer the one that specified arg types.
660 If both do, merge the arg types. Also merge the return types. */
662 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
663 tree p1 = TYPE_ARG_TYPES (t1);
664 tree p2 = TYPE_ARG_TYPES (t2);
667 /* Save space: see if the result is identical to one of the args. */
668 if (valtype == TREE_TYPE (t1) && ! p2)
669 return cp_build_type_attribute_variant (t1, attributes);
670 if (valtype == TREE_TYPE (t2) && ! p1)
671 return cp_build_type_attribute_variant (t2, attributes);
673 /* Simple way if one arg fails to specify argument types. */
674 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
676 rval = build_function_type (valtype, p2);
677 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
678 rval = build_exception_variant (rval, raises);
679 return cp_build_type_attribute_variant (rval, attributes);
681 raises = TYPE_RAISES_EXCEPTIONS (t1);
682 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
684 rval = build_function_type (valtype, p1);
686 rval = build_exception_variant (rval, raises);
687 return cp_build_type_attribute_variant (rval, attributes);
690 rval = build_function_type (valtype, commonparms (p1, p2));
691 t1 = build_exception_variant (rval, raises);
697 /* Get this value the long way, since TYPE_METHOD_BASETYPE
698 is just the main variant of this. */
699 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
700 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
703 /* If this was a member function type, get back to the
704 original type of type member function (i.e., without
705 the class instance variable up front. */
706 t1 = build_function_type (TREE_TYPE (t1),
707 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
708 t2 = build_function_type (TREE_TYPE (t2),
709 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
710 t3 = merge_types (t1, t2);
711 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
712 TYPE_ARG_TYPES (t3));
713 t1 = build_exception_variant (t3, raises);
718 /* There is no need to merge attributes into a TYPENAME_TYPE.
719 When the type is instantiated it will have whatever
720 attributes result from the instantiation. */
725 return cp_build_type_attribute_variant (t1, attributes);
728 /* Return the common type of two types.
729 We assume that comptypes has already been done and returned 1;
730 if that isn't so, this may crash.
732 This is the type for the result of most arithmetic operations
733 if the operands have the given two types. */
736 common_type (tree t1, tree t2)
738 enum tree_code code1;
739 enum tree_code code2;
741 /* If one type is nonsense, bail. */
742 if (t1 == error_mark_node || t2 == error_mark_node)
743 return error_mark_node;
745 code1 = TREE_CODE (t1);
746 code2 = TREE_CODE (t2);
748 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
749 || code1 == COMPLEX_TYPE)
750 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
751 || code2 == COMPLEX_TYPE))
752 return type_after_usual_arithmetic_conversions (t1, t2);
754 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
755 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
756 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
757 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
763 /* Compare two exception specifier types for exactness or subsetness, if
764 allowed. Returns false for mismatch, true for match (same, or
767 [except.spec] "If a class X ... objects of class X or any class publicly
768 and unambiguously derived from X. Similarly, if a pointer type Y * ...
769 exceptions of type Y * or that are pointers to any type publicly and
770 unambiguously derived from Y. Otherwise a function only allows exceptions
771 that have the same type ..."
772 This does not mention cv qualifiers and is different to what throw
773 [except.throw] and catch [except.catch] will do. They will ignore the
774 top level cv qualifiers, and allow qualifiers in the pointer to class
777 We implement the letter of the standard. */
780 comp_except_types (tree a, tree b, bool exact)
782 if (same_type_p (a, b))
786 if (cp_type_quals (a) || cp_type_quals (b))
789 if (TREE_CODE (a) == POINTER_TYPE
790 && TREE_CODE (b) == POINTER_TYPE)
794 if (cp_type_quals (a) || cp_type_quals (b))
798 if (TREE_CODE (a) != RECORD_TYPE
799 || TREE_CODE (b) != RECORD_TYPE)
802 if (ACCESSIBLY_UNIQUELY_DERIVED_P (a, b))
808 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
809 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
810 otherwise it must be exact. Exception lists are unordered, but
811 we've already filtered out duplicates. Most lists will be in order,
812 we should try to make use of that. */
815 comp_except_specs (tree t1, tree t2, bool exact)
824 if (t1 == NULL_TREE) /* T1 is ... */
825 return t2 == NULL_TREE || !exact;
826 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
827 return t2 != NULL_TREE && !TREE_VALUE (t2);
828 if (t2 == NULL_TREE) /* T2 is ... */
830 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
833 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
834 Count how many we find, to determine exactness. For exact matching and
835 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
837 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
839 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
841 tree a = TREE_VALUE (probe);
842 tree b = TREE_VALUE (t2);
844 if (comp_except_types (a, b, exact))
846 if (probe == base && exact)
847 base = TREE_CHAIN (probe);
852 if (probe == NULL_TREE)
855 return !exact || base == NULL_TREE || length == list_length (t1);
858 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
859 [] can match [size]. */
862 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
871 /* The type of the array elements must be the same. */
872 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
875 d1 = TYPE_DOMAIN (t1);
876 d2 = TYPE_DOMAIN (t2);
881 /* If one of the arrays is dimensionless, and the other has a
882 dimension, they are of different types. However, it is valid to
890 declarations for an array object can specify
891 array types that differ by the presence or absence of a major
892 array bound (_dcl.array_). */
894 return allow_redeclaration;
896 /* Check that the dimensions are the same. */
898 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
900 max1 = TYPE_MAX_VALUE (d1);
901 max2 = TYPE_MAX_VALUE (d2);
902 if (processing_template_decl && !abi_version_at_least (2)
903 && !value_dependent_expression_p (max1)
904 && !value_dependent_expression_p (max2))
906 /* With abi-1 we do not fold non-dependent array bounds, (and
907 consequently mangle them incorrectly). We must therefore
908 fold them here, to verify the domains have the same
914 if (!cp_tree_equal (max1, max2))
920 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
921 is a bitwise-or of the COMPARE_* flags. */
924 comptypes (tree t1, tree t2, int strict)
929 /* Suppress errors caused by previously reported errors. */
930 if (t1 == error_mark_node || t2 == error_mark_node)
933 my_friendly_assert (TYPE_P (t1) && TYPE_P (t2), 20030623);
935 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
936 current instantiation. */
937 if (TREE_CODE (t1) == TYPENAME_TYPE)
939 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
941 if (resolved != error_mark_node)
945 if (TREE_CODE (t2) == TYPENAME_TYPE)
947 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
949 if (resolved != error_mark_node)
953 /* If either type is the internal version of sizetype, use the
955 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
957 t1 = TYPE_DOMAIN (t1);
959 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
961 t2 = TYPE_DOMAIN (t2);
963 if (TYPE_PTRMEMFUNC_P (t1))
964 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
965 if (TYPE_PTRMEMFUNC_P (t2))
966 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
968 /* Different classes of types can't be compatible. */
969 if (TREE_CODE (t1) != TREE_CODE (t2))
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
974 if (TREE_CODE (t1) != ARRAY_TYPE
975 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
977 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
984 if (TREE_CODE (t1) != ARRAY_TYPE
985 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
988 if (!(*targetm.comp_type_attributes) (t1, t2))
991 switch (TREE_CODE (t1))
993 case TEMPLATE_TEMPLATE_PARM:
994 case BOUND_TEMPLATE_TEMPLATE_PARM:
995 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
996 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
998 if (!comp_template_parms
999 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1000 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1002 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1004 /* Don't check inheritance. */
1005 strict = COMPARE_STRICT;
1010 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1011 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1012 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1013 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1016 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1018 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1024 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1025 strict & ~COMPARE_REDECLARATION))
1030 case REFERENCE_TYPE:
1031 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1035 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1037 return compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2));
1040 /* Target types must match incl. qualifiers. */
1041 return comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION));
1043 case TEMPLATE_TYPE_PARM:
1044 return (TEMPLATE_TYPE_IDX (t1) == TEMPLATE_TYPE_IDX (t2)
1045 && TEMPLATE_TYPE_LEVEL (t1) == TEMPLATE_TYPE_LEVEL (t2));
1048 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1049 TYPENAME_TYPE_FULLNAME (t2)))
1051 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1053 case UNBOUND_CLASS_TEMPLATE:
1054 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1056 return same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2));
1059 return same_type_p (TREE_TYPE (t1), TREE_TYPE (t2));
1067 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1070 at_least_as_qualified_p (tree type1, tree type2)
1072 int q1 = cp_type_quals (type1);
1073 int q2 = cp_type_quals (type2);
1075 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1076 return (q1 & q2) == q2;
1079 /* Returns 1 if TYPE1 is more qualified than TYPE2. */
1082 more_qualified_p (tree type1, tree type2)
1084 int q1 = cp_type_quals (type1);
1085 int q2 = cp_type_quals (type2);
1087 return q1 != q2 && (q1 & q2) == q2;
1090 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1091 more cv-qualified that TYPE1, and 0 otherwise. */
1094 comp_cv_qualification (tree type1, tree type2)
1096 int q1 = cp_type_quals (type1);
1097 int q2 = cp_type_quals (type2);
1102 if ((q1 & q2) == q2)
1104 else if ((q1 & q2) == q1)
1110 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1111 subset of the cv-qualification signature of TYPE2, and the types
1112 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1115 comp_cv_qual_signature (tree type1, tree type2)
1117 if (comp_ptr_ttypes_real (type2, type1, -1))
1119 else if (comp_ptr_ttypes_real (type1, type2, -1))
1125 /* If two types share a common base type, return that basetype.
1126 If there is not a unique most-derived base type, this function
1127 returns ERROR_MARK_NODE. */
1130 common_base_type (tree tt1, tree tt2)
1132 tree best = NULL_TREE;
1135 /* If one is a baseclass of another, that's good enough. */
1136 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1138 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1141 /* Otherwise, try to find a unique baseclass of TT1
1142 that is shared by TT2, and follow that down. */
1143 for (i = CLASSTYPE_N_BASECLASSES (tt1)-1; i >= 0; i--)
1145 tree basetype = TYPE_BINFO_BASETYPE (tt1, i);
1146 tree trial = common_base_type (basetype, tt2);
1149 if (trial == error_mark_node)
1151 if (best == NULL_TREE)
1153 else if (best != trial)
1154 return error_mark_node;
1159 for (i = CLASSTYPE_N_BASECLASSES (tt2)-1; i >= 0; i--)
1161 tree basetype = TYPE_BINFO_BASETYPE (tt2, i);
1162 tree trial = common_base_type (tt1, basetype);
1165 if (trial == error_mark_node)
1167 if (best == NULL_TREE)
1169 else if (best != trial)
1170 return error_mark_node;
1176 /* Subroutines of `comptypes'. */
1178 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1179 equivalent in the sense that functions with those parameter types
1180 can have equivalent types. The two lists must be equivalent,
1181 element by element. */
1184 compparms (tree parms1, tree parms2)
1188 /* An unspecified parmlist matches any specified parmlist
1189 whose argument types don't need default promotions. */
1191 for (t1 = parms1, t2 = parms2;
1193 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1195 /* If one parmlist is shorter than the other,
1196 they fail to match. */
1199 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1206 /* Process a sizeof or alignof expression where the operand is a
1210 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1212 enum tree_code type_code;
1214 const char *op_name;
1216 my_friendly_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR, 20020720);
1217 if (type == error_mark_node)
1218 return error_mark_node;
1220 if (processing_template_decl)
1222 value = build_min (op, size_type_node, type);
1223 TREE_READONLY (value) = 1;
1227 op_name = operator_name_info[(int) op].name;
1229 type = non_reference (type);
1230 type_code = TREE_CODE (type);
1232 if (type_code == METHOD_TYPE)
1234 if (complain && (pedantic || warn_pointer_arith))
1235 pedwarn ("invalid application of `%s' to a member function", op_name);
1236 value = size_one_node;
1239 value = c_sizeof_or_alignof_type (complete_type (type), op, complain);
1244 /* Process a sizeof or alignof expression where the operand is an
1248 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1250 const char *op_name = operator_name_info[(int) op].name;
1252 if (e == error_mark_node)
1253 return error_mark_node;
1255 if (processing_template_decl)
1257 e = build_min (op, size_type_node, e);
1258 TREE_SIDE_EFFECTS (e) = 0;
1259 TREE_READONLY (e) = 1;
1264 if (TREE_CODE (e) == COMPONENT_REF
1265 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1266 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1268 error ("invalid application of `%s' to a bit-field", op_name);
1271 else if (is_overloaded_fn (e))
1273 pedwarn ("ISO C++ forbids applying `%s' to an expression of function type", op_name);
1276 else if (type_unknown_p (e))
1278 cxx_incomplete_type_error (e, TREE_TYPE (e));
1284 return cxx_sizeof_or_alignof_type (e, op, true);
1288 /* Perform the conversions in [expr] that apply when an lvalue appears
1289 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1290 function-to-pointer conversions.
1292 In addition manifest constants are replaced by their values. */
1295 decay_conversion (tree exp)
1298 enum tree_code code;
1300 type = TREE_TYPE (exp);
1301 code = TREE_CODE (type);
1303 if (code == REFERENCE_TYPE)
1305 exp = convert_from_reference (exp);
1306 type = TREE_TYPE (exp);
1307 code = TREE_CODE (type);
1310 if (type == error_mark_node)
1311 return error_mark_node;
1313 if (type_unknown_p (exp))
1315 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1316 return error_mark_node;
1319 /* Constants can be used directly unless they're not loadable. */
1320 if (TREE_CODE (exp) == CONST_DECL)
1321 exp = DECL_INITIAL (exp);
1322 /* Replace a nonvolatile const static variable with its value. We
1323 don't do this for arrays, though; we want the address of the
1324 first element of the array, not the address of the first element
1325 of its initializing constant. */
1326 else if (code != ARRAY_TYPE)
1328 exp = decl_constant_value (exp);
1329 type = TREE_TYPE (exp);
1332 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1333 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1335 if (code == VOID_TYPE)
1337 error ("void value not ignored as it ought to be");
1338 return error_mark_node;
1340 if (code == METHOD_TYPE)
1342 error ("invalid use of non-static member function");
1343 return error_mark_node;
1345 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1346 return build_unary_op (ADDR_EXPR, exp, 0);
1347 if (code == ARRAY_TYPE)
1352 if (TREE_CODE (exp) == INDIRECT_REF)
1353 return build_nop (build_pointer_type (TREE_TYPE (type)),
1354 TREE_OPERAND (exp, 0));
1356 if (TREE_CODE (exp) == COMPOUND_EXPR)
1358 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1359 return build (COMPOUND_EXPR, TREE_TYPE (op1),
1360 TREE_OPERAND (exp, 0), op1);
1364 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1366 error ("invalid use of non-lvalue array");
1367 return error_mark_node;
1370 ptrtype = build_pointer_type (TREE_TYPE (type));
1372 if (TREE_CODE (exp) == VAR_DECL)
1374 if (!cxx_mark_addressable (exp))
1375 return error_mark_node;
1376 adr = build_nop (ptrtype, build_address (exp));
1377 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
1380 /* This way is better for a COMPONENT_REF since it can
1381 simplify the offset for a component. */
1382 adr = build_unary_op (ADDR_EXPR, exp, 1);
1383 return cp_convert (ptrtype, adr);
1386 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1387 rvalues always have cv-unqualified types. */
1388 if (! CLASS_TYPE_P (type))
1389 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1395 default_conversion (tree exp)
1397 exp = decay_conversion (exp);
1399 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1400 exp = perform_integral_promotions (exp);
1405 /* EXPR is an expression with an integral or enumeration type.
1406 Perform the integral promotions in [conv.prom], and return the
1410 perform_integral_promotions (tree expr)
1415 type = TREE_TYPE (expr);
1416 my_friendly_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type), 20030703);
1417 promoted_type = type_promotes_to (type);
1418 if (type != promoted_type)
1419 expr = cp_convert (promoted_type, expr);
1423 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1427 inline_conversion (tree exp)
1429 if (TREE_CODE (exp) == FUNCTION_DECL)
1430 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1435 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1436 decay_conversion to one. */
1439 string_conv_p (tree totype, tree exp, int warn)
1443 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1446 t = TREE_TYPE (totype);
1447 if (!same_type_p (t, char_type_node)
1448 && !same_type_p (t, wchar_type_node))
1451 if (TREE_CODE (exp) == STRING_CST)
1453 /* Make sure that we don't try to convert between char and wchar_t. */
1454 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1459 /* Is this a string constant which has decayed to 'const char *'? */
1460 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1461 if (!same_type_p (TREE_TYPE (exp), t))
1464 if (TREE_CODE (exp) != ADDR_EXPR
1465 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1469 /* This warning is not very useful, as it complains about printf. */
1470 if (warn && warn_write_strings)
1471 warning ("deprecated conversion from string constant to `%T'", totype);
1476 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1477 can, for example, use as an lvalue. This code used to be in
1478 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1479 expressions, where we're dealing with aggregates. But now it's again only
1480 called from unary_complex_lvalue. The case (in particular) that led to
1481 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1485 rationalize_conditional_expr (enum tree_code code, tree t)
1487 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1488 the first operand is always the one to be used if both operands
1489 are equal, so we know what conditional expression this used to be. */
1490 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1493 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1494 ? LE_EXPR : GE_EXPR),
1495 TREE_OPERAND (t, 0),
1496 TREE_OPERAND (t, 1)),
1497 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1498 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1502 build_conditional_expr (TREE_OPERAND (t, 0),
1503 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1504 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1507 /* Given the TYPE of an anonymous union field inside T, return the
1508 FIELD_DECL for the field. If not found return NULL_TREE. Because
1509 anonymous unions can nest, we must also search all anonymous unions
1510 that are directly reachable. */
1513 lookup_anon_field (tree t, tree type)
1517 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1519 if (TREE_STATIC (field))
1521 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1524 /* If we find it directly, return the field. */
1525 if (DECL_NAME (field) == NULL_TREE
1526 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1531 /* Otherwise, it could be nested, search harder. */
1532 if (DECL_NAME (field) == NULL_TREE
1533 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1535 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1543 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1544 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1545 non-NULL, it indicates the path to the base used to name MEMBER.
1546 If PRESERVE_REFERENCE is true, the expression returned will have
1547 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1548 returned will have the type referred to by the reference.
1550 This function does not perform access control; that is either done
1551 earlier by the parser when the name of MEMBER is resolved to MEMBER
1552 itself, or later when overload resolution selects one of the
1553 functions indicated by MEMBER. */
1556 build_class_member_access_expr (tree object, tree member,
1557 tree access_path, bool preserve_reference)
1561 tree result = NULL_TREE;
1563 if (object == error_mark_node || member == error_mark_node)
1564 return error_mark_node;
1566 if (TREE_CODE (member) == PSEUDO_DTOR_EXPR)
1569 my_friendly_assert (DECL_P (member) || BASELINK_P (member),
1574 The type of the first expression shall be "class object" (of a
1576 object_type = TREE_TYPE (object);
1577 if (!currently_open_class (object_type)
1578 && !complete_type_or_else (object_type, object))
1579 return error_mark_node;
1580 if (!CLASS_TYPE_P (object_type))
1582 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1583 member, object, object_type);
1584 return error_mark_node;
1587 /* The standard does not seem to actually say that MEMBER must be a
1588 member of OBJECT_TYPE. However, that is clearly what is
1590 if (DECL_P (member))
1592 member_scope = DECL_CLASS_CONTEXT (member);
1594 if (TREE_DEPRECATED (member))
1595 warn_deprecated_use (member);
1598 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1599 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1600 presently be the anonymous union. Go outwards until we find a
1601 type related to OBJECT_TYPE. */
1602 while (ANON_AGGR_TYPE_P (member_scope)
1603 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1605 member_scope = TYPE_CONTEXT (member_scope);
1606 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1608 if (TREE_CODE (member) == FIELD_DECL)
1609 error ("invalid use of nonstatic data member '%E'", member);
1611 error ("`%D' is not a member of `%T'", member, object_type);
1612 return error_mark_node;
1615 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1616 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1617 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1619 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1621 object = build_indirect_ref (temp, NULL);
1624 /* In [expr.ref], there is an explicit list of the valid choices for
1625 MEMBER. We check for each of those cases here. */
1626 if (TREE_CODE (member) == VAR_DECL)
1628 /* A static data member. */
1630 /* If OBJECT has side-effects, they are supposed to occur. */
1631 if (TREE_SIDE_EFFECTS (object))
1632 result = build (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1634 else if (TREE_CODE (member) == FIELD_DECL)
1636 /* A non-static data member. */
1641 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1642 && integer_zerop (TREE_OPERAND (object, 0)));
1644 /* Convert OBJECT to the type of MEMBER. */
1645 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1646 TYPE_MAIN_VARIANT (member_scope)))
1651 binfo = lookup_base (access_path ? access_path : object_type,
1652 member_scope, ba_ignore, &kind);
1653 if (binfo == error_mark_node)
1654 return error_mark_node;
1656 /* It is invalid to try to get to a virtual base of a
1657 NULL object. The most common cause is invalid use of
1659 if (null_object_p && kind == bk_via_virtual)
1661 error ("invalid access to non-static data member `%D' of NULL object",
1663 error ("(perhaps the `offsetof' macro was used incorrectly)");
1664 return error_mark_node;
1667 /* Convert to the base. */
1668 object = build_base_path (PLUS_EXPR, object, binfo,
1670 /* If we found the base successfully then we should be able
1671 to convert to it successfully. */
1672 my_friendly_assert (object != error_mark_node,
1676 /* Complain about other invalid uses of offsetof, even though they will
1677 give the right answer. Note that we complain whether or not they
1678 actually used the offsetof macro, since there's no way to know at this
1679 point. So we just give a warning, instead of a pedwarn. */
1680 if (null_object_p && warn_invalid_offsetof
1681 && CLASSTYPE_NON_POD_P (object_type))
1683 warning ("invalid access to non-static data member `%D' of NULL object",
1685 warning ("(perhaps the `offsetof' macro was used incorrectly)");
1688 /* If MEMBER is from an anonymous aggregate, we have converted
1689 OBJECT so that it refers to the class containing the
1690 anonymous union. Generate a reference to the anonymous union
1691 itself, and recur to find MEMBER. */
1692 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1693 /* When this code is called from build_field_call, the
1694 object already has the type of the anonymous union.
1695 That is because the COMPONENT_REF was already
1696 constructed, and was then disassembled before calling
1697 build_field_call. After the function-call code is
1698 cleaned up, this waste can be eliminated. */
1699 && (!same_type_ignoring_top_level_qualifiers_p
1700 (TREE_TYPE (object), DECL_CONTEXT (member))))
1702 tree anonymous_union;
1704 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1705 DECL_CONTEXT (member));
1706 object = build_class_member_access_expr (object,
1708 /*access_path=*/NULL_TREE,
1709 preserve_reference);
1712 /* Compute the type of the field, as described in [expr.ref]. */
1713 type_quals = TYPE_UNQUALIFIED;
1714 member_type = TREE_TYPE (member);
1715 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1717 type_quals = (cp_type_quals (member_type)
1718 | cp_type_quals (object_type));
1720 /* A field is const (volatile) if the enclosing object, or the
1721 field itself, is const (volatile). But, a mutable field is
1722 not const, even within a const object. */
1723 if (DECL_MUTABLE_P (member))
1724 type_quals &= ~TYPE_QUAL_CONST;
1725 member_type = cp_build_qualified_type (member_type, type_quals);
1728 result = fold (build (COMPONENT_REF, member_type, object, member));
1730 /* Mark the expression const or volatile, as appropriate. Even
1731 though we've dealt with the type above, we still have to mark the
1732 expression itself. */
1733 if (type_quals & TYPE_QUAL_CONST)
1734 TREE_READONLY (result) = 1;
1735 else if (type_quals & TYPE_QUAL_VOLATILE)
1736 TREE_THIS_VOLATILE (result) = 1;
1738 else if (BASELINK_P (member))
1740 /* The member is a (possibly overloaded) member function. */
1744 /* If the MEMBER is exactly one static member function, then we
1745 know the type of the expression. Otherwise, we must wait
1746 until overload resolution has been performed. */
1747 functions = BASELINK_FUNCTIONS (member);
1748 if (TREE_CODE (functions) == FUNCTION_DECL
1749 && DECL_STATIC_FUNCTION_P (functions))
1750 type = TREE_TYPE (functions);
1752 type = unknown_type_node;
1753 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1754 base. That will happen when the function is called. */
1755 result = build (COMPONENT_REF, type, object, member);
1757 else if (TREE_CODE (member) == CONST_DECL)
1759 /* The member is an enumerator. */
1761 /* If OBJECT has side-effects, they are supposed to occur. */
1762 if (TREE_SIDE_EFFECTS (object))
1763 result = build (COMPOUND_EXPR, TREE_TYPE (result),
1768 error ("invalid use of `%D'", member);
1769 return error_mark_node;
1772 if (!preserve_reference)
1775 If E2 is declared to have type "reference to T", then ... the
1776 type of E1.E2 is T. */
1777 result = convert_from_reference (result);
1782 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1783 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1786 lookup_destructor (tree object, tree scope, tree dtor_name)
1788 tree object_type = TREE_TYPE (object);
1789 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1791 if (scope && !check_dtor_name (scope, dtor_name))
1793 error ("qualified type `%T' does not match destructor name `~%T'",
1795 return error_mark_node;
1797 if (!same_type_p (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1799 error ("the type being destroyed is `%T', but the destructor refers to `%T'",
1800 TYPE_MAIN_VARIANT (object_type), dtor_type);
1801 return error_mark_node;
1803 if (!TYPE_HAS_DESTRUCTOR (object_type))
1804 return build (PSEUDO_DTOR_EXPR, void_type_node, object, scope,
1806 return lookup_member (object_type, complete_dtor_identifier,
1807 /*protect=*/1, /*want_type=*/false);
1810 /* This function is called by the parser to process a class member
1811 access expression of the form OBJECT.NAME. NAME is a node used by
1812 the parser to represent a name; it is not yet a DECL. It may,
1813 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1814 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1815 there is no reason to do the lookup twice, so the parser keeps the
1819 finish_class_member_access_expr (tree object, tree name)
1824 tree access_path = NULL_TREE;
1825 tree orig_object = object;
1826 tree orig_name = name;
1828 if (object == error_mark_node || name == error_mark_node)
1829 return error_mark_node;
1831 object_type = TREE_TYPE (object);
1833 if (processing_template_decl)
1835 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1836 dependent_type_p (object_type)
1837 /* If NAME is just an IDENTIFIER_NODE, then the expression
1839 || TREE_CODE (object) == IDENTIFIER_NODE
1840 /* If NAME is "f<args>", where either 'f' or 'args' is
1841 dependent, then the expression is dependent. */
1842 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1843 && dependent_template_id_p (TREE_OPERAND (name, 0),
1844 TREE_OPERAND (name, 1)))
1845 /* If NAME is "T::X" where "T" is dependent, then the
1846 expression is dependent. */
1847 || (TREE_CODE (name) == SCOPE_REF
1848 && TYPE_P (TREE_OPERAND (name, 0))
1849 && dependent_type_p (TREE_OPERAND (name, 0))))
1850 return build_min_nt (COMPONENT_REF, object, name);
1851 object = build_non_dependent_expr (object);
1854 if (TREE_CODE (object_type) == REFERENCE_TYPE)
1856 object = convert_from_reference (object);
1857 object_type = TREE_TYPE (object);
1862 The type of the first expression shall be "class object" (of a
1864 if (!currently_open_class (object_type)
1865 && !complete_type_or_else (object_type, object))
1866 return error_mark_node;
1867 if (!CLASS_TYPE_P (object_type))
1869 error ("request for member `%D' in `%E', which is of non-class type `%T'",
1870 name, object, object_type);
1871 return error_mark_node;
1874 if (BASELINK_P (name))
1876 /* A member function that has already been looked up. */
1877 my_friendly_assert ((TREE_CODE (BASELINK_FUNCTIONS (name))
1878 == TEMPLATE_ID_EXPR),
1884 bool is_template_id = false;
1885 tree template_args = NULL_TREE;
1888 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1890 is_template_id = true;
1891 template_args = TREE_OPERAND (name, 1);
1892 name = TREE_OPERAND (name, 0);
1894 if (TREE_CODE (name) == OVERLOAD)
1895 name = DECL_NAME (get_first_fn (name));
1896 else if (DECL_P (name))
1897 name = DECL_NAME (name);
1900 if (TREE_CODE (name) == SCOPE_REF)
1902 /* A qualified name. The qualifying class or namespace `S' has
1903 already been looked up; it is either a TYPE or a
1904 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1905 or a BIT_NOT_EXPR. */
1906 scope = TREE_OPERAND (name, 0);
1907 name = TREE_OPERAND (name, 1);
1908 my_friendly_assert ((CLASS_TYPE_P (scope)
1909 || TREE_CODE (scope) == NAMESPACE_DECL),
1911 my_friendly_assert ((TREE_CODE (name) == IDENTIFIER_NODE
1912 || TREE_CODE (name) == BIT_NOT_EXPR),
1915 /* If SCOPE is a namespace, then the qualified name does not
1916 name a member of OBJECT_TYPE. */
1917 if (TREE_CODE (scope) == NAMESPACE_DECL)
1919 error ("`%D::%D' is not a member of `%T'",
1920 scope, name, object_type);
1921 return error_mark_node;
1924 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
1925 access_path = lookup_base (object_type, scope, ba_check, NULL);
1926 if (access_path == error_mark_node)
1927 return error_mark_node;
1930 error ("`%T' is not a base of `%T'", scope, object_type);
1931 return error_mark_node;
1937 access_path = object_type;
1940 if (TREE_CODE (name) == BIT_NOT_EXPR)
1941 member = lookup_destructor (object, scope, name);
1944 /* Look up the member. */
1945 member = lookup_member (access_path, name, /*protect=*/1,
1946 /*want_type=*/false);
1947 if (member == NULL_TREE)
1949 error ("'%D' has no member named '%E'", object_type, name);
1950 return error_mark_node;
1952 if (member == error_mark_node)
1953 return error_mark_node;
1958 tree template = member;
1960 if (BASELINK_P (template))
1961 template = lookup_template_function (template, template_args);
1964 error ("`%D' is not a member template function", name);
1965 return error_mark_node;
1970 if (TREE_DEPRECATED (member))
1971 warn_deprecated_use (member);
1973 expr = build_class_member_access_expr (object, member, access_path,
1974 /*preserve_reference=*/false);
1975 if (processing_template_decl && expr != error_mark_node)
1976 return build_min_non_dep (COMPONENT_REF, expr,
1977 orig_object, orig_name);
1981 /* Return an expression for the MEMBER_NAME field in the internal
1982 representation of PTRMEM, a pointer-to-member function. (Each
1983 pointer-to-member function type gets its own RECORD_TYPE so it is
1984 more convenient to access the fields by name than by FIELD_DECL.)
1985 This routine converts the NAME to a FIELD_DECL and then creates the
1986 node for the complete expression. */
1989 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
1995 /* This code is a stripped down version of
1996 build_class_member_access_expr. It does not work to use that
1997 routine directly because it expects the object to be of class
1999 ptrmem_type = TREE_TYPE (ptrmem);
2000 my_friendly_assert (TYPE_PTRMEMFUNC_P (ptrmem_type), 20020804);
2001 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2002 /*want_type=*/false);
2003 member_type = cp_build_qualified_type (TREE_TYPE (member),
2004 cp_type_quals (ptrmem_type));
2005 return fold (build (COMPONENT_REF, member_type, ptrmem, member));
2008 /* Given an expression PTR for a pointer, return an expression
2009 for the value pointed to.
2010 ERRORSTRING is the name of the operator to appear in error messages.
2012 This function may need to overload OPERATOR_FNNAME.
2013 Must also handle REFERENCE_TYPEs for C++. */
2016 build_x_indirect_ref (tree expr, const char *errorstring)
2018 tree orig_expr = expr;
2021 if (processing_template_decl)
2023 if (type_dependent_expression_p (expr))
2024 return build_min_nt (INDIRECT_REF, expr);
2025 expr = build_non_dependent_expr (expr);
2028 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2031 rval = build_indirect_ref (expr, errorstring);
2033 if (processing_template_decl && rval != error_mark_node)
2034 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2040 build_indirect_ref (tree ptr, const char *errorstring)
2044 if (ptr == error_mark_node)
2045 return error_mark_node;
2047 if (ptr == current_class_ptr)
2048 return current_class_ref;
2050 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2051 ? ptr : decay_conversion (ptr));
2052 type = TREE_TYPE (pointer);
2054 if (TYPE_PTR_P (type) || TREE_CODE (type) == REFERENCE_TYPE)
2058 If the type of the expression is "pointer to T," the type
2059 of the result is "T."
2061 We must use the canonical variant because certain parts of
2062 the back end, like fold, do pointer comparisons between
2064 tree t = canonical_type_variant (TREE_TYPE (type));
2066 if (VOID_TYPE_P (t))
2068 /* A pointer to incomplete type (other than cv void) can be
2069 dereferenced [expr.unary.op]/1 */
2070 error ("`%T' is not a pointer-to-object type", type);
2071 return error_mark_node;
2073 else if (TREE_CODE (pointer) == ADDR_EXPR
2074 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2075 /* The POINTER was something like `&x'. We simplify `*&x' to
2077 return TREE_OPERAND (pointer, 0);
2080 tree ref = build1 (INDIRECT_REF, t, pointer);
2082 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2083 so that we get the proper error message if the result is used
2084 to assign to. Also, &* is supposed to be a no-op. */
2085 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2086 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2087 TREE_SIDE_EFFECTS (ref)
2088 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2092 /* `pointer' won't be an error_mark_node if we were given a
2093 pointer to member, so it's cool to check for this here. */
2094 else if (TYPE_PTR_TO_MEMBER_P (type))
2095 error ("invalid use of `%s' on pointer to member", errorstring);
2096 else if (pointer != error_mark_node)
2099 error ("invalid type argument of `%s'", errorstring);
2101 error ("invalid type argument");
2103 return error_mark_node;
2106 /* This handles expressions of the form "a[i]", which denotes
2109 This is logically equivalent in C to *(a+i), but we may do it differently.
2110 If A is a variable or a member, we generate a primitive ARRAY_REF.
2111 This avoids forcing the array out of registers, and can work on
2112 arrays that are not lvalues (for example, members of structures returned
2115 If INDEX is of some user-defined type, it must be converted to
2116 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2117 will inherit the type of the array, which will be some pointer type. */
2120 build_array_ref (tree array, tree idx)
2124 error ("subscript missing in array reference");
2125 return error_mark_node;
2128 if (TREE_TYPE (array) == error_mark_node
2129 || TREE_TYPE (idx) == error_mark_node)
2130 return error_mark_node;
2132 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2134 switch (TREE_CODE (array))
2138 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2139 return build (COMPOUND_EXPR, TREE_TYPE (value),
2140 TREE_OPERAND (array, 0), value);
2144 return build_conditional_expr
2145 (TREE_OPERAND (array, 0),
2146 build_array_ref (TREE_OPERAND (array, 1), idx),
2147 build_array_ref (TREE_OPERAND (array, 2), idx));
2153 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE
2154 && TREE_CODE (array) != INDIRECT_REF)
2158 /* Subscripting with type char is likely to lose
2159 on a machine where chars are signed.
2160 So warn on any machine, but optionally.
2161 Don't warn for unsigned char since that type is safe.
2162 Don't warn for signed char because anyone who uses that
2163 must have done so deliberately. */
2164 if (warn_char_subscripts
2165 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2166 warning ("array subscript has type `char'");
2168 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2170 error ("array subscript is not an integer");
2171 return error_mark_node;
2174 /* Apply integral promotions *after* noticing character types.
2175 (It is unclear why we do these promotions -- the standard
2176 does not say that we should. In fact, the natual thing would
2177 seem to be to convert IDX to ptrdiff_t; we're performing
2178 pointer arithmetic.) */
2179 idx = perform_integral_promotions (idx);
2181 /* An array that is indexed by a non-constant
2182 cannot be stored in a register; we must be able to do
2183 address arithmetic on its address.
2184 Likewise an array of elements of variable size. */
2185 if (TREE_CODE (idx) != INTEGER_CST
2186 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2187 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2190 if (!cxx_mark_addressable (array))
2191 return error_mark_node;
2194 /* An array that is indexed by a constant value which is not within
2195 the array bounds cannot be stored in a register either; because we
2196 would get a crash in store_bit_field/extract_bit_field when trying
2197 to access a non-existent part of the register. */
2198 if (TREE_CODE (idx) == INTEGER_CST
2199 && TYPE_VALUES (TREE_TYPE (array))
2200 && ! int_fits_type_p (idx, TYPE_VALUES (TREE_TYPE (array))))
2202 if (!cxx_mark_addressable (array))
2203 return error_mark_node;
2206 if (pedantic && !lvalue_p (array))
2207 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2209 /* Note in C++ it is valid to subscript a `register' array, since
2210 it is valid to take the address of something with that
2211 storage specification. */
2215 while (TREE_CODE (foo) == COMPONENT_REF)
2216 foo = TREE_OPERAND (foo, 0);
2217 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2218 warning ("subscripting array declared `register'");
2221 type = TREE_TYPE (TREE_TYPE (array));
2222 rval = build (ARRAY_REF, type, array, idx);
2223 /* Array ref is const/volatile if the array elements are
2224 or if the array is.. */
2225 TREE_READONLY (rval)
2226 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2227 TREE_SIDE_EFFECTS (rval)
2228 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2229 TREE_THIS_VOLATILE (rval)
2230 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2231 return require_complete_type (fold (rval));
2235 tree ar = default_conversion (array);
2236 tree ind = default_conversion (idx);
2238 /* Put the integer in IND to simplify error checking. */
2239 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2246 if (ar == error_mark_node)
2249 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2251 error ("subscripted value is neither array nor pointer");
2252 return error_mark_node;
2254 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2256 error ("array subscript is not an integer");
2257 return error_mark_node;
2260 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2265 /* Resolve a pointer to member function. INSTANCE is the object
2266 instance to use, if the member points to a virtual member.
2268 This used to avoid checking for virtual functions if basetype
2269 has no virtual functions, according to an earlier ANSI draft.
2270 With the final ISO C++ rules, such an optimization is
2271 incorrect: A pointer to a derived member can be static_cast
2272 to pointer-to-base-member, as long as the dynamic object
2273 later has the right member. */
2276 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2278 if (TREE_CODE (function) == OFFSET_REF)
2279 function = TREE_OPERAND (function, 1);
2281 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2283 tree idx, delta, e1, e2, e3, vtbl, basetype;
2284 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2286 tree instance_ptr = *instance_ptrptr;
2287 tree instance_save_expr = 0;
2288 if (instance_ptr == error_mark_node)
2290 if (TREE_CODE (function) == PTRMEM_CST)
2292 /* Extracting the function address from a pmf is only
2293 allowed with -Wno-pmf-conversions. It only works for
2295 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2296 e1 = convert (fntype, e1);
2301 error ("object missing in use of `%E'", function);
2302 return error_mark_node;
2306 if (TREE_SIDE_EFFECTS (instance_ptr))
2307 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2309 if (TREE_SIDE_EFFECTS (function))
2310 function = save_expr (function);
2312 /* Start by extracting all the information from the PMF itself. */
2313 e3 = PFN_FROM_PTRMEMFUNC (function);
2314 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2315 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2316 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2318 case ptrmemfunc_vbit_in_pfn:
2319 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2320 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2323 case ptrmemfunc_vbit_in_delta:
2324 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2325 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2332 /* Convert down to the right base before using the instance. First
2334 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2335 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2336 basetype, ba_check, NULL);
2337 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype, 1);
2338 if (instance_ptr == error_mark_node)
2339 return error_mark_node;
2340 /* ...and then the delta in the PMF. */
2341 instance_ptr = build (PLUS_EXPR, TREE_TYPE (instance_ptr),
2342 instance_ptr, delta);
2344 /* Hand back the adjusted 'this' argument to our caller. */
2345 *instance_ptrptr = instance_ptr;
2347 /* Next extract the vtable pointer from the object. */
2348 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2350 vtbl = build_indirect_ref (vtbl, NULL);
2352 /* Finally, extract the function pointer from the vtable. */
2353 e2 = fold (build (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx));
2354 e2 = build_indirect_ref (e2, NULL);
2355 TREE_CONSTANT (e2) = 1;
2357 /* When using function descriptors, the address of the
2358 vtable entry is treated as a function pointer. */
2359 if (TARGET_VTABLE_USES_DESCRIPTORS)
2360 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2361 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2363 TREE_TYPE (e2) = TREE_TYPE (e3);
2364 e1 = build_conditional_expr (e1, e2, e3);
2366 /* Make sure this doesn't get evaluated first inside one of the
2367 branches of the COND_EXPR. */
2368 if (instance_save_expr)
2369 e1 = build (COMPOUND_EXPR, TREE_TYPE (e1),
2370 instance_save_expr, e1);
2378 build_function_call (tree function, tree params)
2380 tree fntype, fndecl;
2381 tree coerced_params;
2383 tree name = NULL_TREE;
2385 tree original = function;
2387 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2388 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2389 if (TREE_CODE (function) == NOP_EXPR
2390 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2391 function = TREE_OPERAND (function, 0);
2393 if (TREE_CODE (function) == FUNCTION_DECL)
2395 name = DECL_NAME (function);
2397 mark_used (function);
2400 /* Convert anything with function type to a pointer-to-function. */
2401 if (pedantic && DECL_MAIN_P (function))
2402 pedwarn ("ISO C++ forbids calling `::main' from within program");
2404 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2405 (because calling an inline function does not mean the function
2406 needs to be separately compiled). */
2408 if (DECL_INLINE (function))
2409 function = inline_conversion (function);
2411 function = build_addr_func (function);
2417 function = build_addr_func (function);
2420 if (function == error_mark_node)
2421 return error_mark_node;
2423 fntype = TREE_TYPE (function);
2425 if (TYPE_PTRMEMFUNC_P (fntype))
2427 error ("must use .* or ->* to call pointer-to-member function in `%E (...)'",
2429 return error_mark_node;
2432 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2433 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2435 if (!((TREE_CODE (fntype) == POINTER_TYPE
2436 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2438 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2440 error ("`%E' cannot be used as a function", original);
2441 return error_mark_node;
2444 /* fntype now gets the type of function pointed to. */
2445 fntype = TREE_TYPE (fntype);
2447 /* Convert the parameters to the types declared in the
2448 function prototype, or apply default promotions. */
2450 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2451 params, fndecl, LOOKUP_NORMAL);
2452 if (coerced_params == error_mark_node)
2453 return error_mark_node;
2455 /* Check for errors in format strings. */
2458 check_function_format (NULL, TYPE_ATTRIBUTES (fntype), coerced_params);
2460 /* Recognize certain built-in functions so we can make tree-codes
2461 other than CALL_EXPR. We do this when it enables fold-const.c
2462 to do something useful. */
2464 if (TREE_CODE (function) == ADDR_EXPR
2465 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL
2466 && DECL_BUILT_IN (TREE_OPERAND (function, 0)))
2468 result = expand_tree_builtin (TREE_OPERAND (function, 0),
2469 params, coerced_params);
2474 return build_cxx_call (function, params, coerced_params);
2477 /* Convert the actual parameter expressions in the list VALUES
2478 to the types in the list TYPELIST.
2479 If parmdecls is exhausted, or when an element has NULL as its type,
2480 perform the default conversions.
2482 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2484 This is also where warnings about wrong number of args are generated.
2486 Return a list of expressions for the parameters as converted.
2488 Both VALUES and the returned value are chains of TREE_LIST nodes
2489 with the elements of the list in the TREE_VALUE slots of those nodes.
2491 In C++, unspecified trailing parameters can be filled in with their
2492 default arguments, if such were specified. Do so here. */
2495 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2497 tree typetail, valtail;
2498 tree result = NULL_TREE;
2499 const char *called_thing = 0;
2502 /* Argument passing is always copy-initialization. */
2503 flags |= LOOKUP_ONLYCONVERTING;
2507 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2509 if (DECL_NAME (fndecl) == NULL_TREE
2510 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2511 called_thing = "constructor";
2513 called_thing = "member function";
2516 called_thing = "function";
2519 for (valtail = values, typetail = typelist;
2521 valtail = TREE_CHAIN (valtail), i++)
2523 tree type = typetail ? TREE_VALUE (typetail) : 0;
2524 tree val = TREE_VALUE (valtail);
2526 if (val == error_mark_node)
2527 return error_mark_node;
2529 if (type == void_type_node)
2533 cp_error_at ("too many arguments to %s `%+#D'", called_thing,
2535 error ("at this point in file");
2538 error ("too many arguments to function");
2539 /* In case anybody wants to know if this argument
2542 TREE_TYPE (tree_last (result)) = error_mark_node;
2546 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2547 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2548 if (TREE_CODE (val) == NOP_EXPR
2549 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2550 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2551 val = TREE_OPERAND (val, 0);
2553 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2555 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2556 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2557 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2558 val = decay_conversion (val);
2561 if (val == error_mark_node)
2562 return error_mark_node;
2566 /* Formal parm type is specified by a function prototype. */
2569 if (!COMPLETE_TYPE_P (complete_type (type)))
2572 error ("parameter %P of `%D' has incomplete type `%T'",
2575 error ("parameter %P has incomplete type `%T'", i, type);
2576 parmval = error_mark_node;
2580 parmval = convert_for_initialization
2581 (NULL_TREE, type, val, flags,
2582 "argument passing", fndecl, i);
2583 parmval = convert_for_arg_passing (type, parmval);
2586 if (parmval == error_mark_node)
2587 return error_mark_node;
2589 result = tree_cons (NULL_TREE, parmval, result);
2593 if (TREE_CODE (TREE_TYPE (val)) == REFERENCE_TYPE)
2594 val = convert_from_reference (val);
2596 if (fndecl && DECL_BUILT_IN (fndecl)
2597 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2598 /* Don't do ellipsis conversion for __built_in_constant_p
2599 as this will result in spurious warnings for non-POD
2601 val = require_complete_type (val);
2603 val = convert_arg_to_ellipsis (val);
2605 result = tree_cons (NULL_TREE, val, result);
2609 typetail = TREE_CHAIN (typetail);
2612 if (typetail != 0 && typetail != void_list_node)
2614 /* See if there are default arguments that can be used. */
2615 if (TREE_PURPOSE (typetail)
2616 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2618 for (; typetail != void_list_node; ++i)
2621 = convert_default_arg (TREE_VALUE (typetail),
2622 TREE_PURPOSE (typetail),
2625 if (parmval == error_mark_node)
2626 return error_mark_node;
2628 result = tree_cons (0, parmval, result);
2629 typetail = TREE_CHAIN (typetail);
2630 /* ends with `...'. */
2631 if (typetail == NULL_TREE)
2639 cp_error_at ("too few arguments to %s `%+#D'",
2640 called_thing, fndecl);
2641 error ("at this point in file");
2644 error ("too few arguments to function");
2645 return error_mark_list;
2649 return nreverse (result);
2652 /* Build a binary-operation expression, after performing default
2653 conversions on the operands. CODE is the kind of expression to build. */
2656 build_x_binary_op (enum tree_code code, tree arg1, tree arg2)
2665 if (processing_template_decl)
2667 if (type_dependent_expression_p (arg1)
2668 || type_dependent_expression_p (arg2))
2669 return build_min_nt (code, arg1, arg2);
2670 arg1 = build_non_dependent_expr (arg1);
2671 arg2 = build_non_dependent_expr (arg2);
2674 if (code == DOTSTAR_EXPR)
2675 expr = build_m_component_ref (arg1, arg2);
2677 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE);
2679 if (processing_template_decl && expr != error_mark_node)
2680 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2685 /* Build a binary-operation expression without default conversions.
2686 CODE is the kind of expression to build.
2687 This function differs from `build' in several ways:
2688 the data type of the result is computed and recorded in it,
2689 warnings are generated if arg data types are invalid,
2690 special handling for addition and subtraction of pointers is known,
2691 and some optimization is done (operations on narrow ints
2692 are done in the narrower type when that gives the same result).
2693 Constant folding is also done before the result is returned.
2695 Note that the operands will never have enumeral types
2696 because either they have just had the default conversions performed
2697 or they have both just been converted to some other type in which
2698 the arithmetic is to be done.
2700 C++: must do special pointer arithmetic when implementing
2701 multiple inheritance, and deal with pointer to member functions. */
2704 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2705 int convert_p ATTRIBUTE_UNUSED)
2708 enum tree_code code0, code1;
2711 /* Expression code to give to the expression when it is built.
2712 Normally this is CODE, which is what the caller asked for,
2713 but in some special cases we change it. */
2714 enum tree_code resultcode = code;
2716 /* Data type in which the computation is to be performed.
2717 In the simplest cases this is the common type of the arguments. */
2718 tree result_type = NULL;
2720 /* Nonzero means operands have already been type-converted
2721 in whatever way is necessary.
2722 Zero means they need to be converted to RESULT_TYPE. */
2725 /* Nonzero means create the expression with this type, rather than
2727 tree build_type = 0;
2729 /* Nonzero means after finally constructing the expression
2730 convert it to this type. */
2731 tree final_type = 0;
2733 /* Nonzero if this is an operation like MIN or MAX which can
2734 safely be computed in short if both args are promoted shorts.
2735 Also implies COMMON.
2736 -1 indicates a bitwise operation; this makes a difference
2737 in the exact conditions for when it is safe to do the operation
2738 in a narrower mode. */
2741 /* Nonzero if this is a comparison operation;
2742 if both args are promoted shorts, compare the original shorts.
2743 Also implies COMMON. */
2744 int short_compare = 0;
2746 /* Nonzero if this is a right-shift operation, which can be computed on the
2747 original short and then promoted if the operand is a promoted short. */
2748 int short_shift = 0;
2750 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2753 /* Apply default conversions. */
2757 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2758 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2759 || code == TRUTH_XOR_EXPR)
2761 if (!really_overloaded_fn (op0))
2762 op0 = decay_conversion (op0);
2763 if (!really_overloaded_fn (op1))
2764 op1 = decay_conversion (op1);
2768 if (!really_overloaded_fn (op0))
2769 op0 = default_conversion (op0);
2770 if (!really_overloaded_fn (op1))
2771 op1 = default_conversion (op1);
2774 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2775 STRIP_TYPE_NOPS (op0);
2776 STRIP_TYPE_NOPS (op1);
2778 /* DTRT if one side is an overloaded function, but complain about it. */
2779 if (type_unknown_p (op0))
2781 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2782 if (t != error_mark_node)
2784 pedwarn ("assuming cast to type `%T' from overloaded function",
2789 if (type_unknown_p (op1))
2791 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2792 if (t != error_mark_node)
2794 pedwarn ("assuming cast to type `%T' from overloaded function",
2800 type0 = TREE_TYPE (op0);
2801 type1 = TREE_TYPE (op1);
2803 /* The expression codes of the data types of the arguments tell us
2804 whether the arguments are integers, floating, pointers, etc. */
2805 code0 = TREE_CODE (type0);
2806 code1 = TREE_CODE (type1);
2808 /* If an error was already reported for one of the arguments,
2809 avoid reporting another error. */
2811 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2812 return error_mark_node;
2817 /* Handle the pointer + int case. */
2818 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2819 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2820 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2821 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2827 /* Subtraction of two similar pointers.
2828 We must subtract them as integers, then divide by object size. */
2829 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2830 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2832 return pointer_diff (op0, op1, common_type (type0, type1));
2833 /* Handle pointer minus int. Just like pointer plus int. */
2834 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2835 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2844 case TRUNC_DIV_EXPR:
2846 case FLOOR_DIV_EXPR:
2847 case ROUND_DIV_EXPR:
2848 case EXACT_DIV_EXPR:
2849 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2850 || code0 == COMPLEX_TYPE)
2851 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2852 || code1 == COMPLEX_TYPE))
2854 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2855 warning ("division by zero in `%E / 0'", op0);
2856 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2857 warning ("division by zero in `%E / 0.'", op0);
2859 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2860 resultcode = RDIV_EXPR;
2862 /* When dividing two signed integers, we have to promote to int.
2863 unless we divide by a constant != -1. Note that default
2864 conversion will have been performed on the operands at this
2865 point, so we have to dig out the original type to find out if
2867 shorten = ((TREE_CODE (op0) == NOP_EXPR
2868 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2869 || (TREE_CODE (op1) == INTEGER_CST
2870 && ! integer_all_onesp (op1)));
2879 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2883 case TRUNC_MOD_EXPR:
2884 case FLOOR_MOD_EXPR:
2885 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2886 warning ("division by zero in `%E %% 0'", op0);
2887 else if (code1 == REAL_TYPE && real_zerop (op1))
2888 warning ("division by zero in `%E %% 0.'", op0);
2890 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2892 /* Although it would be tempting to shorten always here, that loses
2893 on some targets, since the modulo instruction is undefined if the
2894 quotient can't be represented in the computation mode. We shorten
2895 only if unsigned or if dividing by something we know != -1. */
2896 shorten = ((TREE_CODE (op0) == NOP_EXPR
2897 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2898 || (TREE_CODE (op1) == INTEGER_CST
2899 && ! integer_all_onesp (op1)));
2904 case TRUTH_ANDIF_EXPR:
2905 case TRUTH_ORIF_EXPR:
2906 case TRUTH_AND_EXPR:
2908 result_type = boolean_type_node;
2911 /* Shift operations: result has same type as first operand;
2912 always convert second operand to int.
2913 Also set SHORT_SHIFT if shifting rightward. */
2916 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2918 result_type = type0;
2919 if (TREE_CODE (op1) == INTEGER_CST)
2921 if (tree_int_cst_lt (op1, integer_zero_node))
2922 warning ("right shift count is negative");
2925 if (! integer_zerop (op1))
2927 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2928 warning ("right shift count >= width of type");
2931 /* Convert the shift-count to an integer, regardless of
2932 size of value being shifted. */
2933 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2934 op1 = cp_convert (integer_type_node, op1);
2935 /* Avoid converting op1 to result_type later. */
2941 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2943 result_type = type0;
2944 if (TREE_CODE (op1) == INTEGER_CST)
2946 if (tree_int_cst_lt (op1, integer_zero_node))
2947 warning ("left shift count is negative");
2948 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2949 warning ("left shift count >= width of type");
2951 /* Convert the shift-count to an integer, regardless of
2952 size of value being shifted. */
2953 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2954 op1 = cp_convert (integer_type_node, op1);
2955 /* Avoid converting op1 to result_type later. */
2962 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2964 result_type = type0;
2965 if (TREE_CODE (op1) == INTEGER_CST)
2967 if (tree_int_cst_lt (op1, integer_zero_node))
2968 warning ("%s rotate count is negative",
2969 (code == LROTATE_EXPR) ? "left" : "right");
2970 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2971 warning ("%s rotate count >= width of type",
2972 (code == LROTATE_EXPR) ? "left" : "right");
2974 /* Convert the shift-count to an integer, regardless of
2975 size of value being shifted. */
2976 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2977 op1 = cp_convert (integer_type_node, op1);
2983 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
2984 warning ("comparing floating point with == or != is unsafe");
2986 build_type = boolean_type_node;
2987 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2988 || code0 == COMPLEX_TYPE)
2989 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2990 || code1 == COMPLEX_TYPE))
2992 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2993 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
2994 result_type = composite_pointer_type (type0, type1, op0, op1,
2996 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
2997 && null_ptr_cst_p (op1))
2998 result_type = type0;
2999 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3000 && null_ptr_cst_p (op0))
3001 result_type = type1;
3002 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3004 result_type = type0;
3005 error ("ISO C++ forbids comparison between pointer and integer");
3007 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3009 result_type = type1;
3010 error ("ISO C++ forbids comparison between pointer and integer");
3012 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3014 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3015 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3016 result_type = TREE_TYPE (op0);
3018 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3019 return cp_build_binary_op (code, op1, op0);
3020 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3021 && same_type_p (type0, type1))
3023 /* E will be the final comparison. */
3025 /* E1 and E2 are for scratch. */
3033 if (TREE_SIDE_EFFECTS (op0))
3034 op0 = save_expr (op0);
3035 if (TREE_SIDE_EFFECTS (op1))
3036 op1 = save_expr (op1);
3041 && (!op0.pfn || op0.delta == op1.delta))
3043 The reason for the `!op0.pfn' bit is that a NULL
3044 pointer-to-member is any member with a zero PFN; the
3045 DELTA field is unspecified. */
3046 pfn0 = pfn_from_ptrmemfunc (op0);
3047 pfn1 = pfn_from_ptrmemfunc (op1);
3048 delta0 = build_ptrmemfunc_access_expr (op0,
3050 delta1 = build_ptrmemfunc_access_expr (op1,
3052 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3053 e2 = cp_build_binary_op (EQ_EXPR,
3055 cp_convert (TREE_TYPE (pfn0),
3056 integer_zero_node));
3057 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3058 e2 = build (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3059 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3060 if (code == EQ_EXPR)
3062 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3064 else if ((TYPE_PTRMEMFUNC_P (type0)
3065 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0), type1))
3066 || (TYPE_PTRMEMFUNC_P (type1)
3067 && same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1), type0)))
3073 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3074 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3076 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3077 result_type = composite_pointer_type (type0, type1, op0, op1,
3085 build_type = boolean_type_node;
3086 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3087 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3089 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3090 result_type = composite_pointer_type (type0, type1, op0, op1,
3092 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3093 && integer_zerop (op1))
3094 result_type = type0;
3095 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3096 && integer_zerop (op0))
3097 result_type = type1;
3098 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3100 result_type = type0;
3101 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3103 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3105 result_type = type1;
3106 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3110 case UNORDERED_EXPR:
3117 build_type = integer_type_node;
3118 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3120 error ("unordered comparison on non-floating point argument");
3121 return error_mark_node;
3130 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3132 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
3134 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3136 if (shorten || common || short_compare)
3137 result_type = common_type (type0, type1);
3139 /* For certain operations (which identify themselves by shorten != 0)
3140 if both args were extended from the same smaller type,
3141 do the arithmetic in that type and then extend.
3143 shorten !=0 and !=1 indicates a bitwise operation.
3144 For them, this optimization is safe only if
3145 both args are zero-extended or both are sign-extended.
3146 Otherwise, we might change the result.
3147 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3148 but calculated in (unsigned short) it would be (unsigned short)-1. */
3150 if (shorten && none_complex)
3152 int unsigned0, unsigned1;
3153 tree arg0 = get_narrower (op0, &unsigned0);
3154 tree arg1 = get_narrower (op1, &unsigned1);
3155 /* UNS is 1 if the operation to be done is an unsigned one. */
3156 int uns = TREE_UNSIGNED (result_type);
3159 final_type = result_type;
3161 /* Handle the case that OP0 does not *contain* a conversion
3162 but it *requires* conversion to FINAL_TYPE. */
3164 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3165 unsigned0 = TREE_UNSIGNED (TREE_TYPE (op0));
3166 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3167 unsigned1 = TREE_UNSIGNED (TREE_TYPE (op1));
3169 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3171 /* For bitwise operations, signedness of nominal type
3172 does not matter. Consider only how operands were extended. */
3176 /* Note that in all three cases below we refrain from optimizing
3177 an unsigned operation on sign-extended args.
3178 That would not be valid. */
3180 /* Both args variable: if both extended in same way
3181 from same width, do it in that width.
3182 Do it unsigned if args were zero-extended. */
3183 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3184 < TYPE_PRECISION (result_type))
3185 && (TYPE_PRECISION (TREE_TYPE (arg1))
3186 == TYPE_PRECISION (TREE_TYPE (arg0)))
3187 && unsigned0 == unsigned1
3188 && (unsigned0 || !uns))
3189 result_type = c_common_signed_or_unsigned_type
3190 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3191 else if (TREE_CODE (arg0) == INTEGER_CST
3192 && (unsigned1 || !uns)
3193 && (TYPE_PRECISION (TREE_TYPE (arg1))
3194 < TYPE_PRECISION (result_type))
3195 && (type = c_common_signed_or_unsigned_type
3196 (unsigned1, TREE_TYPE (arg1)),
3197 int_fits_type_p (arg0, type)))
3199 else if (TREE_CODE (arg1) == INTEGER_CST
3200 && (unsigned0 || !uns)
3201 && (TYPE_PRECISION (TREE_TYPE (arg0))
3202 < TYPE_PRECISION (result_type))
3203 && (type = c_common_signed_or_unsigned_type
3204 (unsigned0, TREE_TYPE (arg0)),
3205 int_fits_type_p (arg1, type)))
3209 /* Shifts can be shortened if shifting right. */
3214 tree arg0 = get_narrower (op0, &unsigned_arg);
3216 final_type = result_type;
3218 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3219 unsigned_arg = TREE_UNSIGNED (TREE_TYPE (op0));
3221 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3222 /* We can shorten only if the shift count is less than the
3223 number of bits in the smaller type size. */
3224 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3225 /* If arg is sign-extended and then unsigned-shifted,
3226 we can simulate this with a signed shift in arg's type
3227 only if the extended result is at least twice as wide
3228 as the arg. Otherwise, the shift could use up all the
3229 ones made by sign-extension and bring in zeros.
3230 We can't optimize that case at all, but in most machines
3231 it never happens because available widths are 2**N. */
3232 && (!TREE_UNSIGNED (final_type)
3234 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3235 <= TYPE_PRECISION (result_type))))
3237 /* Do an unsigned shift if the operand was zero-extended. */
3239 = c_common_signed_or_unsigned_type (unsigned_arg,
3241 /* Convert value-to-be-shifted to that type. */
3242 if (TREE_TYPE (op0) != result_type)
3243 op0 = cp_convert (result_type, op0);
3248 /* Comparison operations are shortened too but differently.
3249 They identify themselves by setting short_compare = 1. */
3253 /* Don't write &op0, etc., because that would prevent op0
3254 from being kept in a register.
3255 Instead, make copies of the our local variables and
3256 pass the copies by reference, then copy them back afterward. */
3257 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3258 enum tree_code xresultcode = resultcode;
3260 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3262 return cp_convert (boolean_type_node, val);
3263 op0 = xop0, op1 = xop1;
3265 resultcode = xresultcode;
3268 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3269 && warn_sign_compare
3270 /* Do not warn until the template is instantiated; we cannot
3271 bound the ranges of the arguments until that point. */
3272 && !processing_template_decl)
3274 int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0));
3275 int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1));
3277 int unsignedp0, unsignedp1;
3278 tree primop0 = get_narrower (op0, &unsignedp0);
3279 tree primop1 = get_narrower (op1, &unsignedp1);
3281 /* Check for comparison of different enum types. */
3282 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3283 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3284 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3285 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3287 warning ("comparison between types `%#T' and `%#T'",
3288 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3291 /* Give warnings for comparisons between signed and unsigned
3292 quantities that may fail. */
3293 /* Do the checking based on the original operand trees, so that
3294 casts will be considered, but default promotions won't be. */
3296 /* Do not warn if the comparison is being done in a signed type,
3297 since the signed type will only be chosen if it can represent
3298 all the values of the unsigned type. */
3299 if (! TREE_UNSIGNED (result_type))
3301 /* Do not warn if both operands are unsigned. */
3302 else if (op0_signed == op1_signed)
3304 /* Do not warn if the signed quantity is an unsuffixed
3305 integer literal (or some static constant expression
3306 involving such literals or a conditional expression
3307 involving such literals) and it is non-negative. */
3308 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3309 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3311 /* Do not warn if the comparison is an equality operation,
3312 the unsigned quantity is an integral constant and it does
3313 not use the most significant bit of result_type. */
3314 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3315 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3316 && int_fits_type_p (orig_op1, c_common_signed_type
3318 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3319 && int_fits_type_p (orig_op0, c_common_signed_type
3323 warning ("comparison between signed and unsigned integer expressions");
3325 /* Warn if two unsigned values are being compared in a size
3326 larger than their original size, and one (and only one) is the
3327 result of a `~' operator. This comparison will always fail.
3329 Also warn if one operand is a constant, and the constant does not
3330 have all bits set that are set in the ~ operand when it is
3333 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3334 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3336 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3337 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3338 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3339 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3341 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3344 HOST_WIDE_INT constant, mask;
3348 if (host_integerp (primop0, 0))
3351 unsignedp = unsignedp1;
3352 constant = tree_low_cst (primop0, 0);
3357 unsignedp = unsignedp0;
3358 constant = tree_low_cst (primop1, 0);
3361 bits = TYPE_PRECISION (TREE_TYPE (primop));
3362 if (bits < TYPE_PRECISION (result_type)
3363 && bits < HOST_BITS_PER_LONG && unsignedp)
3365 mask = (~ (HOST_WIDE_INT) 0) << bits;
3366 if ((mask & constant) != mask)
3367 warning ("comparison of promoted ~unsigned with constant");
3370 else if (unsignedp0 && unsignedp1
3371 && (TYPE_PRECISION (TREE_TYPE (primop0))
3372 < TYPE_PRECISION (result_type))
3373 && (TYPE_PRECISION (TREE_TYPE (primop1))
3374 < TYPE_PRECISION (result_type)))
3375 warning ("comparison of promoted ~unsigned with unsigned");
3380 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
3381 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3382 Then the expression will be built.
3383 It will be given type FINAL_TYPE if that is nonzero;
3384 otherwise, it will be given type RESULT_TYPE. */
3388 error ("invalid operands of types `%T' and `%T' to binary `%O'",
3389 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3390 return error_mark_node;
3393 /* Issue warnings about peculiar, but valid, uses of NULL. */
3394 if (/* It's reasonable to use pointer values as operands of &&
3395 and ||, so NULL is no exception. */
3396 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3397 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3398 (orig_op0 == null_node
3399 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3400 /* Or vice versa. */
3401 || (orig_op1 == null_node
3402 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3403 /* Or, both are NULL and the operation was not a comparison. */
3404 || (orig_op0 == null_node && orig_op1 == null_node
3405 && code != EQ_EXPR && code != NE_EXPR)))
3406 /* Some sort of arithmetic operation involving NULL was
3407 performed. Note that pointer-difference and pointer-addition
3408 have already been handled above, and so we don't end up here in
3410 warning ("NULL used in arithmetic");
3414 if (TREE_TYPE (op0) != result_type)
3415 op0 = cp_convert (result_type, op0);
3416 if (TREE_TYPE (op1) != result_type)
3417 op1 = cp_convert (result_type, op1);
3419 if (op0 == error_mark_node || op1 == error_mark_node)
3420 return error_mark_node;
3423 if (build_type == NULL_TREE)
3424 build_type = result_type;
3427 tree result = build (resultcode, build_type, op0, op1);
3430 folded = fold (result);
3431 if (folded == result)
3432 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
3433 if (final_type != 0)
3434 return cp_convert (final_type, folded);
3439 /* Return a tree for the sum or difference (RESULTCODE says which)
3440 of pointer PTROP and integer INTOP. */
3443 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3445 tree res_type = TREE_TYPE (ptrop);
3447 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3448 in certain circumstance (when it's valid to do so). So we need
3449 to make sure it's complete. We don't need to check here, if we
3450 can actually complete it at all, as those checks will be done in
3451 pointer_int_sum() anyway. */
3452 complete_type (TREE_TYPE (res_type));
3454 return pointer_int_sum (resultcode, ptrop, fold (intop));
3457 /* Return a tree for the difference of pointers OP0 and OP1.
3458 The resulting tree has type int. */
3461 pointer_diff (tree op0, tree op1, tree ptrtype)
3463 tree result, folded;
3464 tree restype = ptrdiff_type_node;
3465 tree target_type = TREE_TYPE (ptrtype);
3467 if (!complete_type_or_else (target_type, NULL_TREE))
3468 return error_mark_node;
3470 if (pedantic || warn_pointer_arith)
3472 if (TREE_CODE (target_type) == VOID_TYPE)
3473 pedwarn ("ISO C++ forbids using pointer of type `void *' in subtraction");
3474 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3475 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3476 if (TREE_CODE (target_type) == METHOD_TYPE)
3477 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3480 /* First do the subtraction as integers;
3481 then drop through to build the divide operator. */
3483 op0 = cp_build_binary_op (MINUS_EXPR,
3484 cp_convert (restype, op0),
3485 cp_convert (restype, op1));
3487 /* This generates an error if op1 is a pointer to an incomplete type. */
3488 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3489 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3491 op1 = (TYPE_PTROB_P (ptrtype)
3492 ? size_in_bytes (target_type)
3493 : integer_one_node);
3495 /* Do the division. */
3497 result = build (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3499 folded = fold (result);
3500 if (folded == result)
3501 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
3505 /* Construct and perhaps optimize a tree representation
3506 for a unary operation. CODE, a tree_code, specifies the operation
3507 and XARG is the operand. */
3510 build_x_unary_op (enum tree_code code, tree xarg)
3512 tree orig_expr = xarg;
3516 if (processing_template_decl)
3518 if (type_dependent_expression_p (xarg))
3519 return build_min_nt (code, xarg, NULL_TREE);
3520 xarg = build_non_dependent_expr (xarg);
3525 /* & rec, on incomplete RECORD_TYPEs is the simple opr &, not an
3527 if (code == ADDR_EXPR
3528 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3529 && ((IS_AGGR_TYPE_CODE (TREE_CODE (TREE_TYPE (xarg)))
3530 && !COMPLETE_TYPE_P (TREE_TYPE (xarg)))
3531 || (TREE_CODE (xarg) == OFFSET_REF)))
3532 /* Don't look for a function. */;
3534 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE);
3535 if (!exp && code == ADDR_EXPR)
3537 /* A pointer to member-function can be formed only by saying
3539 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3540 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3542 if (TREE_CODE (xarg) != OFFSET_REF)
3544 error ("invalid use of '%E' to form a pointer-to-member-function. Use a qualified-id.",
3546 return error_mark_node;
3550 error ("parenthesis around '%E' cannot be used to form a pointer-to-member-function",
3552 PTRMEM_OK_P (xarg) = 1;
3556 if (TREE_CODE (xarg) == OFFSET_REF)
3558 ptrmem = PTRMEM_OK_P (xarg);
3560 if (!ptrmem && !flag_ms_extensions
3561 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3563 /* A single non-static member, make sure we don't allow a
3564 pointer-to-member. */
3565 xarg = build (OFFSET_REF, TREE_TYPE (xarg),
3566 TREE_OPERAND (xarg, 0),
3567 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3568 PTRMEM_OK_P (xarg) = ptrmem;
3571 else if (TREE_CODE (xarg) == TARGET_EXPR)
3572 warning ("taking address of temporary");
3573 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3574 if (TREE_CODE (exp) == ADDR_EXPR)
3575 PTRMEM_OK_P (exp) = ptrmem;
3578 if (processing_template_decl && exp != error_mark_node)
3579 return build_min_non_dep (code, exp, orig_expr,
3580 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3584 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3585 constants, where a null value is represented by an INTEGER_CST of
3589 cp_truthvalue_conversion (tree expr)
3591 tree type = TREE_TYPE (expr);
3592 if (TYPE_PTRMEM_P (type))
3593 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3595 return c_common_truthvalue_conversion (expr);
3598 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3601 condition_conversion (tree expr)
3604 if (processing_template_decl)
3606 t = perform_implicit_conversion (boolean_type_node, expr);
3607 t = fold (build1 (CLEANUP_POINT_EXPR, boolean_type_node, t));
3611 /* Return an ADDR_EXPR giving the address of T. This function
3612 attempts no optimizations or simplifications; it is a low-level
3616 build_address (tree t)
3620 if (error_operand_p (t) || !cxx_mark_addressable (t))
3621 return error_mark_node;
3623 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3625 TREE_CONSTANT (addr) = 1;
3630 /* Return a NOP_EXPR converting EXPR to TYPE. */
3633 build_nop (tree type, tree expr)
3637 if (type == error_mark_node || error_operand_p (expr))
3640 nop = build1 (NOP_EXPR, type, expr);
3641 if (TREE_CONSTANT (expr))
3642 TREE_CONSTANT (nop) = 1;
3647 /* C++: Must handle pointers to members.
3649 Perhaps type instantiation should be extended to handle conversion
3650 from aggregates to types we don't yet know we want? (Or are those
3651 cases typically errors which should be reported?)
3653 NOCONVERT nonzero suppresses the default promotions
3654 (such as from short to int). */
3657 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3659 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3662 const char *errstring = NULL;
3665 if (arg == error_mark_node)
3666 return error_mark_node;
3671 /* This is used for unary plus, because a CONVERT_EXPR
3672 is enough to prevent anybody from looking inside for
3673 associativity, but won't generate any code. */
3674 if (!(arg = build_expr_type_conversion
3675 (WANT_ARITH | WANT_ENUM | WANT_POINTER, arg, true)))
3676 errstring = "wrong type argument to unary plus";
3680 arg = default_conversion (arg);
3681 arg = build1 (NON_LVALUE_EXPR, TREE_TYPE (arg), arg);
3682 TREE_CONSTANT (arg) = TREE_CONSTANT (TREE_OPERAND (arg, 0));
3687 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3688 errstring = "wrong type argument to unary minus";
3689 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3690 arg = perform_integral_promotions (arg);
3694 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3698 arg = default_conversion (arg);
3700 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3702 errstring = "wrong type argument to bit-complement";
3703 else if (!noconvert)
3704 arg = perform_integral_promotions (arg);
3708 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3709 errstring = "wrong type argument to abs";
3710 else if (!noconvert)
3711 arg = default_conversion (arg);
3715 /* Conjugating a real value is a no-op, but allow it anyway. */
3716 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3717 errstring = "wrong type argument to conjugation";
3718 else if (!noconvert)
3719 arg = default_conversion (arg);
3722 case TRUTH_NOT_EXPR:
3723 arg = perform_implicit_conversion (boolean_type_node, arg);
3724 val = invert_truthvalue (arg);
3725 if (arg != error_mark_node)
3727 errstring = "in argument to unary !";
3734 if (TREE_CODE (arg) == COMPLEX_CST)
3735 return TREE_REALPART (arg);
3736 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3737 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3742 if (TREE_CODE (arg) == COMPLEX_CST)
3743 return TREE_IMAGPART (arg);
3744 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3745 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
3747 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3749 case PREINCREMENT_EXPR:
3750 case POSTINCREMENT_EXPR:
3751 case PREDECREMENT_EXPR:
3752 case POSTDECREMENT_EXPR:
3753 /* Handle complex lvalues (when permitted)
3754 by reduction to simpler cases. */
3756 val = unary_complex_lvalue (code, arg);
3760 /* Increment or decrement the real part of the value,
3761 and don't change the imaginary part. */
3762 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3766 arg = stabilize_reference (arg);
3767 real = build_unary_op (REALPART_EXPR, arg, 1);
3768 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3769 return build (COMPLEX_EXPR, TREE_TYPE (arg),
3770 build_unary_op (code, real, 1), imag);
3773 /* Report invalid types. */
3775 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3778 if (code == PREINCREMENT_EXPR)
3779 errstring ="no pre-increment operator for type";
3780 else if (code == POSTINCREMENT_EXPR)
3781 errstring ="no post-increment operator for type";
3782 else if (code == PREDECREMENT_EXPR)
3783 errstring ="no pre-decrement operator for type";
3785 errstring ="no post-decrement operator for type";
3789 /* Report something read-only. */
3791 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3792 || TREE_READONLY (arg))
3793 readonly_error (arg, ((code == PREINCREMENT_EXPR
3794 || code == POSTINCREMENT_EXPR)
3795 ? "increment" : "decrement"),
3800 tree result_type = TREE_TYPE (arg);
3802 arg = get_unwidened (arg, 0);
3803 argtype = TREE_TYPE (arg);
3805 /* ARM $5.2.5 last annotation says this should be forbidden. */
3806 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3807 pedwarn ("ISO C++ forbids %sing an enum",
3808 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3809 ? "increment" : "decrement");
3811 /* Compute the increment. */
3813 if (TREE_CODE (argtype) == POINTER_TYPE)
3815 tree type = complete_type (TREE_TYPE (argtype));
3817 if (!COMPLETE_OR_VOID_TYPE_P (type))
3818 error ("cannot %s a pointer to incomplete type `%T'",
3819 ((code == PREINCREMENT_EXPR
3820 || code == POSTINCREMENT_EXPR)
3821 ? "increment" : "decrement"), TREE_TYPE (argtype));
3822 else if ((pedantic || warn_pointer_arith)
3823 && !TYPE_PTROB_P (argtype))
3824 pedwarn ("ISO C++ forbids %sing a pointer of type `%T'",
3825 ((code == PREINCREMENT_EXPR
3826 || code == POSTINCREMENT_EXPR)
3827 ? "increment" : "decrement"), argtype);
3828 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3831 inc = integer_one_node;
3833 inc = cp_convert (argtype, inc);
3835 /* Handle incrementing a cast-expression. */
3837 switch (TREE_CODE (arg))
3842 case FIX_TRUNC_EXPR:
3843 case FIX_FLOOR_EXPR:
3844 case FIX_ROUND_EXPR:
3847 tree incremented, modify, value, compound;
3848 if (! lvalue_p (arg) && pedantic)
3849 pedwarn ("cast to non-reference type used as lvalue");
3850 arg = stabilize_reference (arg);
3851 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
3854 value = save_expr (arg);
3855 incremented = build (((code == PREINCREMENT_EXPR
3856 || code == POSTINCREMENT_EXPR)
3857 ? PLUS_EXPR : MINUS_EXPR),
3858 argtype, value, inc);
3860 modify = build_modify_expr (arg, NOP_EXPR, incremented);
3861 compound = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value);
3863 /* Eliminate warning about unused result of + or -. */
3864 TREE_NO_UNUSED_WARNING (compound) = 1;
3872 /* Complain about anything else that is not a true lvalue. */
3873 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3874 || code == POSTINCREMENT_EXPR)
3875 ? "increment" : "decrement")))
3876 return error_mark_node;
3878 /* Forbid using -- on `bool'. */
3879 if (TREE_TYPE (arg) == boolean_type_node)
3881 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
3883 error ("invalid use of `--' on bool variable `%D'", arg);
3884 return error_mark_node;
3886 val = boolean_increment (code, arg);
3889 val = build (code, TREE_TYPE (arg), arg, inc);
3891 TREE_SIDE_EFFECTS (val) = 1;
3892 return cp_convert (result_type, val);
3896 /* Note that this operation never does default_conversion
3897 regardless of NOCONVERT. */
3899 argtype = lvalue_type (arg);
3901 if (TREE_CODE (arg) == OFFSET_REF)
3904 if (TREE_CODE (argtype) == REFERENCE_TYPE)
3908 build_pointer_type (TREE_TYPE (argtype)), arg);
3909 TREE_CONSTANT (arg) = TREE_CONSTANT (TREE_OPERAND (arg, 0));
3912 else if (pedantic && DECL_MAIN_P (arg))
3914 pedwarn ("ISO C++ forbids taking address of function `::main'");
3916 /* Let &* cancel out to simplify resulting code. */
3917 if (TREE_CODE (arg) == INDIRECT_REF)
3919 /* We don't need to have `current_class_ptr' wrapped in a
3920 NON_LVALUE_EXPR node. */
3921 if (arg == current_class_ref)
3922 return current_class_ptr;
3924 arg = TREE_OPERAND (arg, 0);
3925 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
3929 build_pointer_type (TREE_TYPE (TREE_TYPE (arg))), arg);
3930 TREE_CONSTANT (arg) = TREE_CONSTANT (TREE_OPERAND (arg, 0));
3932 else if (lvalue_p (arg))
3933 /* Don't let this be an lvalue. */
3934 return non_lvalue (arg);
3938 /* For &x[y], return x+y. */
3939 if (TREE_CODE (arg) == ARRAY_REF)
3941 if (!cxx_mark_addressable (TREE_OPERAND (arg, 0)))
3942 return error_mark_node;
3943 return cp_build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
3944 TREE_OPERAND (arg, 1));
3947 /* Uninstantiated types are all functions. Taking the
3948 address of a function is a no-op, so just return the
3951 if (TREE_CODE (arg) == IDENTIFIER_NODE
3952 && IDENTIFIER_OPNAME_P (arg))
3955 /* We don't know the type yet, so just work around the problem.
3956 We know that this will resolve to an lvalue. */
3957 return build1 (ADDR_EXPR, unknown_type_node, arg);
3960 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
3961 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
3963 /* They're trying to take the address of a unique non-static
3964 member function. This is ill-formed (except in MS-land),
3965 but let's try to DTRT.
3966 Note: We only handle unique functions here because we don't
3967 want to complain if there's a static overload; non-unique
3968 cases will be handled by instantiate_type. But we need to
3969 handle this case here to allow casts on the resulting PMF.
3970 We could defer this in non-MS mode, but it's easier to give
3971 a useful error here. */
3973 /* Inside constant member functions, the `this' pointer
3974 contains an extra const qualifier. TYPE_MAIN_VARIANT
3975 is used here to remove this const from the diagnostics
3976 and the created OFFSET_REF. */
3977 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
3978 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
3980 if (! flag_ms_extensions)
3982 if (current_class_type
3983 && TREE_OPERAND (arg, 0) == current_class_ref)
3984 /* An expression like &memfn. */
3985 pedwarn ("ISO C++ forbids taking the address of an unqualified"
3986 " or parenthesized non-static member function to form"
3987 " a pointer to member function. Say `&%T::%D'",
3990 pedwarn ("ISO C++ forbids taking the address of a bound member"
3991 " function to form a pointer to member function."
3995 arg = build_offset_ref (base, name, /*address_p=*/true);
3999 if (type_unknown_p (arg))
4000 return build1 (ADDR_EXPR, unknown_type_node, arg);
4002 /* Handle complex lvalues (when permitted)
4003 by reduction to simpler cases. */
4004 val = unary_complex_lvalue (code, arg);
4008 switch (TREE_CODE (arg))
4013 case FIX_TRUNC_EXPR:
4014 case FIX_FLOOR_EXPR:
4015 case FIX_ROUND_EXPR:
4017 if (! lvalue_p (arg) && pedantic)
4018 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4025 /* Allow the address of a constructor if all the elements
4027 if (TREE_CODE (arg) == CONSTRUCTOR && TREE_HAS_CONSTRUCTOR (arg)
4028 && TREE_CONSTANT (arg))
4030 /* Anything not already handled and not a true memory reference
4032 else if (TREE_CODE (argtype) != FUNCTION_TYPE
4033 && TREE_CODE (argtype) != METHOD_TYPE
4034 && !lvalue_or_else (arg, "unary `&'"))
4035 return error_mark_node;
4037 if (argtype != error_mark_node)
4038 argtype = build_pointer_type (argtype);
4043 if (TREE_CODE (arg) != COMPONENT_REF)
4044 addr = build_address (arg);
4045 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4047 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4049 /* We can only get here with a single static member
4051 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL
4052 && DECL_STATIC_FUNCTION_P (fn),
4055 addr = build_address (fn);
4056 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4057 /* Do not lose object's side effects. */
4058 addr = build (COMPOUND_EXPR, TREE_TYPE (addr),
4059 TREE_OPERAND (arg, 0), addr);
4061 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4063 error ("attempt to take address of bit-field structure member `%D'",
4064 TREE_OPERAND (arg, 1));
4065 return error_mark_node;
4069 /* Unfortunately we cannot just build an address
4070 expression here, because we would not handle
4071 address-constant-expressions or offsetof correctly. */
4072 tree field = TREE_OPERAND (arg, 1);
4073 tree rval = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), 0);
4074 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (rval)),
4075 decl_type_context (field),
4078 rval = build_base_path (PLUS_EXPR, rval, binfo, 1);
4079 rval = build_nop (argtype, rval);
4080 addr = fold (build (PLUS_EXPR, argtype, rval,
4081 cp_convert (argtype, byte_position (field))));
4084 if (TREE_CODE (argtype) == POINTER_TYPE
4085 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4087 build_ptrmemfunc_type (argtype);
4088 addr = build_ptrmemfunc (argtype, addr, 0);
4101 argtype = TREE_TYPE (arg);
4102 return fold (build1 (code, argtype, arg));
4105 error ("%s", errstring);
4106 return error_mark_node;
4109 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4110 for certain kinds of expressions which are not really lvalues
4111 but which we can accept as lvalues.
4113 If ARG is not a kind of expression we can handle, return zero. */
4116 unary_complex_lvalue (enum tree_code code, tree arg)
4118 /* Handle (a, b) used as an "lvalue". */
4119 if (TREE_CODE (arg) == COMPOUND_EXPR)
4121 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4122 return build (COMPOUND_EXPR, TREE_TYPE (real_result),
4123 TREE_OPERAND (arg, 0), real_result);
4126 /* Handle (a ? b : c) used as an "lvalue". */
4127 if (TREE_CODE (arg) == COND_EXPR
4128 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4129 return rationalize_conditional_expr (code, arg);
4131 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4132 if (TREE_CODE (arg) == MODIFY_EXPR
4133 || TREE_CODE (arg) == PREINCREMENT_EXPR
4134 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4136 tree lvalue = TREE_OPERAND (arg, 0);
4137 if (TREE_SIDE_EFFECTS (lvalue))
4139 lvalue = stabilize_reference (lvalue);
4140 arg = build (TREE_CODE (arg), TREE_TYPE (arg),
4141 lvalue, TREE_OPERAND (arg, 1));
4143 return unary_complex_lvalue
4144 (code, build (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4147 if (code != ADDR_EXPR)
4150 /* Handle (a = b) used as an "lvalue" for `&'. */
4151 if (TREE_CODE (arg) == MODIFY_EXPR
4152 || TREE_CODE (arg) == INIT_EXPR)
4154 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4155 arg = build (COMPOUND_EXPR, TREE_TYPE (real_result), arg, real_result);
4156 TREE_NO_UNUSED_WARNING (arg) = 1;
4160 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4161 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4162 || TREE_CODE (arg) == OFFSET_REF)
4166 my_friendly_assert (TREE_CODE (arg) != SCOPE_REF, 313);
4168 if (TREE_CODE (arg) != OFFSET_REF)
4171 t = TREE_OPERAND (arg, 1);
4173 /* Check all this code for right semantics. */
4174 if (TREE_CODE (t) == FUNCTION_DECL)
4176 if (DECL_DESTRUCTOR_P (t))
4177 error ("taking address of destructor");
4178 return build_unary_op (ADDR_EXPR, t, 0);
4180 if (TREE_CODE (t) == VAR_DECL)
4181 return build_unary_op (ADDR_EXPR, t, 0);
4186 if (TREE_OPERAND (arg, 0)
4187 && ! is_dummy_object (TREE_OPERAND (arg, 0))
4188 && TREE_CODE (t) != FIELD_DECL)
4190 error ("taking address of bound pointer-to-member expression");
4191 return error_mark_node;
4193 if (!PTRMEM_OK_P (arg))
4194 return build_unary_op (code, arg, 0);
4196 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4198 error ("cannot create pointer to reference member `%D'", t);
4199 return error_mark_node;
4202 type = build_ptrmem_type (DECL_FIELD_CONTEXT (t), TREE_TYPE (t));
4203 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4209 /* We permit compiler to make function calls returning
4210 objects of aggregate type look like lvalues. */
4214 if (TREE_CODE (targ) == SAVE_EXPR)
4215 targ = TREE_OPERAND (targ, 0);
4217 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4219 if (TREE_CODE (arg) == SAVE_EXPR)
4222 targ = build_cplus_new (TREE_TYPE (arg), arg);
4223 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4226 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4227 return build (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4228 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4231 /* Don't let anything else be handled specially. */
4235 /* Mark EXP saying that we need to be able to take the
4236 address of it; it should not be allocated in a register.
4237 Value is true if successful.
4239 C++: we do not allow `current_class_ptr' to be addressable. */
4242 cxx_mark_addressable (tree exp)
4247 switch (TREE_CODE (x))
4254 x = TREE_OPERAND (x, 0);
4258 if (x == current_class_ptr)
4260 error ("cannot take the address of `this', which is an rvalue expression");
4261 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4267 /* Caller should not be trying to mark initialized
4268 constant fields addressable. */
4269 my_friendly_assert (DECL_LANG_SPECIFIC (x) == 0
4270 || DECL_IN_AGGR_P (x) == 0
4272 || DECL_EXTERNAL (x), 314);
4277 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4278 && !DECL_ARTIFICIAL (x) && extra_warnings)
4279 warning ("address requested for `%D', which is declared `register'",
4281 TREE_ADDRESSABLE (x) = 1;
4282 put_var_into_stack (x, /*rescan=*/true);
4286 TREE_ADDRESSABLE (x) = 1;
4287 TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (x)) = 1;
4291 TREE_ADDRESSABLE (x) = 1;
4295 TREE_ADDRESSABLE (x) = 1;
4296 cxx_mark_addressable (TREE_OPERAND (x, 0));
4304 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4307 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4309 tree orig_ifexp = ifexp;
4310 tree orig_op1 = op1;
4311 tree orig_op2 = op2;
4314 if (processing_template_decl)
4316 /* The standard says that the expression is type-dependent if
4317 IFEXP is type-dependent, even though the eventual type of the
4318 expression doesn't dependent on IFEXP. */
4319 if (type_dependent_expression_p (ifexp)
4320 /* As a GNU extension, the middle operand may be omitted. */
4321 || (op1 && type_dependent_expression_p (op1))
4322 || type_dependent_expression_p (op2))
4323 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4324 ifexp = build_non_dependent_expr (ifexp);
4326 op1 = build_non_dependent_expr (op1);
4327 op2 = build_non_dependent_expr (op2);
4330 expr = build_conditional_expr (ifexp, op1, op2);
4331 if (processing_template_decl && expr != error_mark_node)
4332 return build_min_non_dep (COND_EXPR, expr,
4333 orig_ifexp, orig_op1, orig_op2);
4337 /* Given a list of expressions, return a compound expression
4338 that performs them all and returns the value of the last of them. */
4340 tree build_x_compound_expr_from_list (tree list, const char *msg)
4342 tree expr = TREE_VALUE (list);
4344 if (TREE_CHAIN (list))
4347 pedwarn ("%s expression list treated as compound expression", msg);
4349 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4350 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4356 /* Handle overloading of the ',' operator when needed. */
4359 build_x_compound_expr (tree op1, tree op2)
4362 tree orig_op1 = op1;
4363 tree orig_op2 = op2;
4365 if (processing_template_decl)
4367 if (type_dependent_expression_p (op1)
4368 || type_dependent_expression_p (op2))
4369 return build_min_nt (COMPOUND_EXPR, op1, op2);
4370 op1 = build_non_dependent_expr (op1);
4371 op2 = build_non_dependent_expr (op2);
4374 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE);
4376 result = build_compound_expr (op1, op2);
4378 if (processing_template_decl && result != error_mark_node)
4379 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4384 /* Build a compound expression. */
4387 build_compound_expr (tree lhs, tree rhs)
4389 lhs = decl_constant_value (lhs);
4390 lhs = convert_to_void (lhs, "left-hand operand of comma");
4392 if (lhs == error_mark_node || rhs == error_mark_node)
4393 return error_mark_node;
4395 if (TREE_CODE (rhs) == TARGET_EXPR)
4397 /* If the rhs is a TARGET_EXPR, then build the compound
4398 expression inside the target_expr's initializer. This
4399 helps the compiler to eliminate unnecessary temporaries. */
4400 tree init = TREE_OPERAND (rhs, 1);
4402 init = build (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4403 TREE_OPERAND (rhs, 1) = init;
4408 return build (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4411 /* Issue an error message if casting from SRC_TYPE to DEST_TYPE casts
4412 away constness. DESCRIPTION explains what operation is taking
4416 check_for_casting_away_constness (tree src_type, tree dest_type,
4417 const char *description)
4419 if (casts_away_constness (src_type, dest_type))
4420 error ("%s from type `%T' to type `%T' casts away constness",
4421 description, src_type, dest_type);
4424 /* Return an expression representing static_cast<TYPE>(EXPR). */
4427 build_static_cast (tree type, tree expr)
4432 if (type == error_mark_node || expr == error_mark_node)
4433 return error_mark_node;
4435 if (processing_template_decl)
4437 expr = build_min (STATIC_CAST_EXPR, type, expr);
4438 /* We don't know if it will or will not have side effects. */
4439 TREE_SIDE_EFFECTS (expr) = 1;
4443 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4444 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4445 if (TREE_CODE (type) != REFERENCE_TYPE
4446 && TREE_CODE (expr) == NOP_EXPR
4447 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4448 expr = TREE_OPERAND (expr, 0);
4450 intype = TREE_TYPE (expr);
4452 /* [expr.static.cast]
4454 An lvalue of type "cv1 B", where B is a class type, can be cast
4455 to type "reference to cv2 D", where D is a class derived (clause
4456 _class.derived_) from B, if a valid standard conversion from
4457 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4458 same cv-qualification as, or greater cv-qualification than, cv1,
4459 and B is not a virtual base class of D. */
4460 /* We check this case before checking the validity of "TYPE t =
4461 EXPR;" below because for this case:
4464 struct D : public B { D(const B&); };
4466 void f() { static_cast<const D&>(b); }
4468 we want to avoid constructing a new D. The standard is not
4469 completely clear about this issue, but our interpretation is
4470 consistent with other compilers. */
4471 if (TREE_CODE (type) == REFERENCE_TYPE
4472 && CLASS_TYPE_P (TREE_TYPE (type))
4473 && CLASS_TYPE_P (intype)
4474 && real_lvalue_p (expr)
4475 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4476 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4477 build_pointer_type (TYPE_MAIN_VARIANT
4478 (TREE_TYPE (type))))
4479 && at_least_as_qualified_p (TREE_TYPE (type), intype))
4481 /* There is a standard conversion from "D*" to "B*" even if "B"
4482 is ambiguous or inaccessible. Therefore, we ask lookup_base
4483 to check these conditions. */
4484 tree base = lookup_base (TREE_TYPE (type), intype, ba_check, NULL);
4486 /* Convert from "B*" to "D*". This function will check that "B"
4487 is not a virtual base of "D". */
4488 expr = build_base_path (MINUS_EXPR, build_address (expr),
4489 base, /*nonnull=*/false);
4490 /* Convert the pointer to a reference -- but then remember that
4491 there are no expressions with reference type in C++. */
4492 return convert_from_reference (build_nop (type, expr));
4495 /* [expr.static.cast]
4497 An expression e can be explicitly converted to a type T using a
4498 static_cast of the form static_cast<T>(e) if the declaration T
4499 t(e);" is well-formed, for some invented temporary variable
4501 result = perform_direct_initialization_if_possible (type, expr);
4503 return convert_from_reference (result);
4505 /* [expr.static.cast]
4507 Any expression can be explicitly converted to type cv void. */
4508 if (TREE_CODE (type) == VOID_TYPE)
4509 return convert_to_void (expr, /*implicit=*/NULL);
4511 /* [expr.static.cast]
4513 The inverse of any standard conversion sequence (clause _conv_),
4514 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4515 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4516 (_conv.bool_) conversions, can be performed explicitly using
4517 static_cast subject to the restriction that the explicit
4518 conversion does not cast away constness (_expr.const.cast_), and
4519 the following additional rules for specific cases: */
4520 /* For reference, the conversions not excluded are: integral
4521 promotions, floating point promotion, integral conversions,
4522 floating point conversions, floating-integral conversions,
4523 pointer conversions, and pointer to member conversions. */
4524 if ((ARITHMETIC_TYPE_P (type) && ARITHMETIC_TYPE_P (intype))
4527 A value of integral _or enumeration_ type can be explicitly
4528 converted to an enumeration type. */
4529 || (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
4530 && INTEGRAL_OR_ENUMERATION_TYPE_P (intype)))
4531 /* Really, build_c_cast should defer to this function rather
4532 than the other way around. */
4533 return build_c_cast (type, expr);
4535 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4536 && CLASS_TYPE_P (TREE_TYPE (type))
4537 && CLASS_TYPE_P (TREE_TYPE (intype))
4538 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4539 (TREE_TYPE (intype))),
4540 build_pointer_type (TYPE_MAIN_VARIANT
4541 (TREE_TYPE (type)))))
4545 check_for_casting_away_constness (intype, type, "static_cast");
4546 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype), ba_check,
4548 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4551 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4552 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4559 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4560 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4562 if (TYPE_PTRMEM_P (type))
4564 t1 = (build_ptrmem_type
4566 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4567 t2 = (build_ptrmem_type
4569 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4576 if (can_convert (t1, t2))
4578 check_for_casting_away_constness (intype, type, "static_cast");
4579 if (TYPE_PTRMEM_P (type))
4583 if (TREE_CODE (expr) == PTRMEM_CST)
4584 expr = cplus_expand_constant (expr);
4585 delta = get_delta_difference (c1, c2, /*force=*/1);
4586 if (!integer_zerop (delta))
4587 expr = cp_build_binary_op (PLUS_EXPR,
4588 build_nop (ptrdiff_type_node, expr),
4590 return build_nop (type, expr);
4593 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4598 /* [expr.static.cast]
4600 An rvalue of type "pointer to cv void" can be explicitly
4601 converted to a pointer to object type. A value of type pointer
4602 to object converted to "pointer to cv void" and back to the
4603 original pointer type will have its original value. */
4604 if (TREE_CODE (intype) == POINTER_TYPE
4605 && VOID_TYPE_P (TREE_TYPE (intype))
4606 && TYPE_PTROB_P (type))
4608 check_for_casting_away_constness (intype, type, "static_cast");
4609 return build_nop (type, expr);
4612 error ("invalid static_cast from type `%T' to type `%T'", intype, type);
4613 return error_mark_node;
4617 build_reinterpret_cast (tree type, tree expr)
4621 if (type == error_mark_node || expr == error_mark_node)
4622 return error_mark_node;
4624 if (processing_template_decl)
4626 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
4628 if (!TREE_SIDE_EFFECTS (t)
4629 && type_dependent_expression_p (expr))
4630 /* There might turn out to be side effects inside expr. */
4631 TREE_SIDE_EFFECTS (t) = 1;
4635 if (TREE_CODE (type) != REFERENCE_TYPE)
4637 expr = decay_conversion (expr);
4639 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4640 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4641 if (TREE_CODE (expr) == NOP_EXPR
4642 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4643 expr = TREE_OPERAND (expr, 0);
4646 intype = TREE_TYPE (expr);
4648 if (TREE_CODE (type) == REFERENCE_TYPE)
4650 if (! real_lvalue_p (expr))
4652 error ("invalid reinterpret_cast of an rvalue expression of type `%T' to type `%T'", intype, type);
4653 return error_mark_node;
4655 expr = build_unary_op (ADDR_EXPR, expr, 0);
4656 if (expr != error_mark_node)
4657 expr = build_reinterpret_cast
4658 (build_pointer_type (TREE_TYPE (type)), expr);
4659 if (expr != error_mark_node)
4660 expr = build_indirect_ref (expr, 0);
4663 else if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4664 return build_static_cast (type, expr);
4666 if (TYPE_PTR_P (type) && (TREE_CODE (intype) == INTEGER_TYPE
4667 || TREE_CODE (intype) == ENUMERAL_TYPE))
4669 else if (TREE_CODE (type) == INTEGER_TYPE && TYPE_PTR_P (intype))
4671 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
4672 pedwarn ("reinterpret_cast from `%T' to `%T' loses precision",
4675 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
4676 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4678 expr = decl_constant_value (expr);
4679 return fold (build1 (NOP_EXPR, type, expr));
4681 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4682 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
4684 check_for_casting_away_constness (intype, type, "reinterpret_cast");
4685 expr = decl_constant_value (expr);
4686 return fold (build1 (NOP_EXPR, type, expr));
4688 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
4689 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
4691 pedwarn ("ISO C++ forbids casting between pointer-to-function and pointer-to-object");
4692 expr = decl_constant_value (expr);
4693 return fold (build1 (NOP_EXPR, type, expr));
4697 error ("invalid reinterpret_cast from type `%T' to type `%T'",
4699 return error_mark_node;
4702 return cp_convert (type, expr);
4706 build_const_cast (tree type, tree expr)
4710 if (type == error_mark_node || expr == error_mark_node)
4711 return error_mark_node;
4713 if (processing_template_decl)
4715 tree t = build_min (CONST_CAST_EXPR, type, expr);
4717 if (!TREE_SIDE_EFFECTS (t)
4718 && type_dependent_expression_p (expr))
4719 /* There might turn out to be side effects inside expr. */
4720 TREE_SIDE_EFFECTS (t) = 1;
4724 if (!POINTER_TYPE_P (type))
4725 error ("invalid use of const_cast with type `%T', which is not a pointer, reference, nor a pointer-to-data-member type", type);
4726 else if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
4728 error ("invalid use of const_cast with type `%T', which is a pointer or reference to a function type", type);
4729 return error_mark_node;
4732 if (TREE_CODE (type) != REFERENCE_TYPE)
4734 expr = decay_conversion (expr);
4736 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4737 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4738 if (TREE_CODE (expr) == NOP_EXPR
4739 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4740 expr = TREE_OPERAND (expr, 0);
4743 intype = TREE_TYPE (expr);
4745 if (same_type_ignoring_top_level_qualifiers_p (intype, type))
4746 return build_static_cast (type, expr);
4747 else if (TREE_CODE (type) == REFERENCE_TYPE)
4749 if (! real_lvalue_p (expr))
4751 error ("invalid const_cast of an rvalue of type `%T' to type `%T'", intype, type);
4752 return error_mark_node;
4755 if (comp_ptr_ttypes_const (TREE_TYPE (type), intype))
4757 expr = build_unary_op (ADDR_EXPR, expr, 0);
4758 expr = build1 (NOP_EXPR, type, expr);
4759 return convert_from_reference (expr);
4762 else if (((TREE_CODE (type) == POINTER_TYPE
4763 && TREE_CODE (intype) == POINTER_TYPE)
4764 || (TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype)))
4765 && comp_ptr_ttypes_const (TREE_TYPE (type), TREE_TYPE (intype)))
4766 return cp_convert (type, expr);
4768 error ("invalid const_cast from type `%T' to type `%T'", intype, type);
4769 return error_mark_node;
4772 /* Build an expression representing a cast to type TYPE of expression EXPR.
4774 ALLOW_NONCONVERTING is true if we should allow non-converting constructors
4775 when doing the cast. */
4778 build_c_cast (tree type, tree expr)
4783 if (type == error_mark_node || expr == error_mark_node)
4784 return error_mark_node;
4786 if (processing_template_decl)
4788 tree t = build_min (CAST_EXPR, type,
4789 tree_cons (NULL_TREE, value, NULL_TREE));
4790 /* We don't know if it will or will not have side effects. */
4791 TREE_SIDE_EFFECTS (t) = 1;
4795 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4796 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4797 if (TREE_CODE (type) != REFERENCE_TYPE
4798 && TREE_CODE (value) == NOP_EXPR
4799 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
4800 value = TREE_OPERAND (value, 0);
4802 if (TREE_CODE (type) == ARRAY_TYPE)
4804 /* Allow casting from T1* to T2[] because Cfront allows it.
4805 NIHCL uses it. It is not valid ISO C++ however. */
4806 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
4808 pedwarn ("ISO C++ forbids casting to an array type `%T'", type);
4809 type = build_pointer_type (TREE_TYPE (type));
4813 error ("ISO C++ forbids casting to an array type `%T'", type);
4814 return error_mark_node;
4818 if (TREE_CODE (type) == FUNCTION_TYPE
4819 || TREE_CODE (type) == METHOD_TYPE)
4821 error ("invalid cast to function type `%T'", type);
4822 return error_mark_node;
4825 if (TREE_CODE (type) == VOID_TYPE)
4827 /* Conversion to void does not cause any of the normal function to
4828 * pointer, array to pointer and lvalue to rvalue decays. */
4830 value = convert_to_void (value, /*implicit=*/NULL);
4834 if (!complete_type_or_else (type, NULL_TREE))
4835 return error_mark_node;
4837 /* Convert functions and arrays to pointers and
4838 convert references to their expanded types,
4839 but don't convert any other types. If, however, we are
4840 casting to a class type, there's no reason to do this: the
4841 cast will only succeed if there is a converting constructor,
4842 and the default conversions will be done at that point. In
4843 fact, doing the default conversion here is actually harmful
4847 struct S { S(const A&); };
4849 since we don't want the array-to-pointer conversion done. */
4850 if (!IS_AGGR_TYPE (type))
4852 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
4853 || (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE
4854 /* Don't do the default conversion on a ->* expression. */
4855 && ! (TREE_CODE (type) == POINTER_TYPE
4856 && bound_pmf_p (value)))
4857 || TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
4858 || TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4859 value = decay_conversion (value);
4861 else if (TREE_CODE (TREE_TYPE (value)) == REFERENCE_TYPE)
4862 /* However, even for class types, we still need to strip away
4863 the reference type, since the call to convert_force below
4864 does not expect the input expression to be of reference
4866 value = convert_from_reference (value);
4868 otype = TREE_TYPE (value);
4870 /* Optionally warn about potentially worrisome casts. */
4873 && TREE_CODE (type) == POINTER_TYPE
4874 && TREE_CODE (otype) == POINTER_TYPE
4875 && !at_least_as_qualified_p (TREE_TYPE (type),
4877 warning ("cast from `%T' to `%T' discards qualifiers from pointer target type",
4880 if (TREE_CODE (type) == INTEGER_TYPE
4881 && TYPE_PTR_P (otype)
4882 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
4883 warning ("cast from pointer to integer of different size");
4885 if (TYPE_PTR_P (type)
4886 && TREE_CODE (otype) == INTEGER_TYPE
4887 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
4888 /* Don't warn about converting any constant. */
4889 && !TREE_CONSTANT (value))
4890 warning ("cast to pointer from integer of different size");
4892 if (TREE_CODE (type) == REFERENCE_TYPE)
4893 value = (convert_from_reference
4894 (convert_to_reference (type, value, CONV_C_CAST,
4895 LOOKUP_COMPLAIN, NULL_TREE)));
4900 value = decl_constant_value (value);
4903 value = convert_force (type, value, CONV_C_CAST);
4905 /* Ignore any integer overflow caused by the cast. */
4906 if (TREE_CODE (value) == INTEGER_CST)
4908 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
4909 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
4913 /* Warn about possible alignment problems. Do this here when we will have
4914 instantiated any necessary template types. */
4915 if (STRICT_ALIGNMENT && warn_cast_align
4916 && TREE_CODE (type) == POINTER_TYPE
4917 && TREE_CODE (otype) == POINTER_TYPE
4918 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
4919 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
4920 && COMPLETE_TYPE_P (TREE_TYPE (otype))
4921 && COMPLETE_TYPE_P (TREE_TYPE (type))
4922 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
4923 warning ("cast from `%T' to `%T' increases required alignment of target type",
4926 /* Always produce some operator for an explicit cast,
4927 so we can tell (for -pedantic) that the cast is no lvalue. */
4928 if (TREE_CODE (type) != REFERENCE_TYPE && value == expr
4929 && real_lvalue_p (value))
4930 value = non_lvalue (value);
4935 /* Build an assignment expression of lvalue LHS from value RHS.
4936 MODIFYCODE is the code for a binary operator that we use
4937 to combine the old value of LHS with RHS to get the new value.
4938 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
4940 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
4943 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
4947 tree lhstype = TREE_TYPE (lhs);
4948 tree olhstype = lhstype;
4949 tree olhs = NULL_TREE;
4951 /* Avoid duplicate error messages from operands that had errors. */
4952 if (lhs == error_mark_node || rhs == error_mark_node)
4953 return error_mark_node;
4955 /* Handle control structure constructs used as "lvalues". */
4956 switch (TREE_CODE (lhs))
4958 /* Handle --foo = 5; as these are valid constructs in C++. */
4959 case PREDECREMENT_EXPR:
4960 case PREINCREMENT_EXPR:
4961 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
4962 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
4963 stabilize_reference (TREE_OPERAND (lhs, 0)),
4964 TREE_OPERAND (lhs, 1));
4965 return build (COMPOUND_EXPR, lhstype,
4967 build_modify_expr (TREE_OPERAND (lhs, 0),
4970 /* Handle (a, b) used as an "lvalue". */
4972 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
4974 if (newrhs == error_mark_node)
4975 return error_mark_node;
4976 return build (COMPOUND_EXPR, lhstype,
4977 TREE_OPERAND (lhs, 0), newrhs);
4980 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
4981 lhs = build (TREE_CODE (lhs), TREE_TYPE (lhs),
4982 stabilize_reference (TREE_OPERAND (lhs, 0)),
4983 TREE_OPERAND (lhs, 1));
4984 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
4985 if (newrhs == error_mark_node)
4986 return error_mark_node;
4987 return build (COMPOUND_EXPR, lhstype, lhs, newrhs);
4989 /* Handle (a ? b : c) used as an "lvalue". */
4992 /* Produce (a ? (b = rhs) : (c = rhs))
4993 except that the RHS goes through a save-expr
4994 so the code to compute it is only emitted once. */
4996 tree preeval = NULL_TREE;
4998 rhs = stabilize_expr (rhs, &preeval);
5000 /* Check this here to avoid odd errors when trying to convert
5001 a throw to the type of the COND_EXPR. */
5002 if (!lvalue_or_else (lhs, "assignment"))
5003 return error_mark_node;
5005 cond = build_conditional_expr
5006 (TREE_OPERAND (lhs, 0),
5007 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5008 TREE_OPERAND (lhs, 1)),
5010 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5011 TREE_OPERAND (lhs, 2)),
5014 if (cond == error_mark_node)
5016 /* Make sure the code to compute the rhs comes out
5017 before the split. */
5018 return build (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5025 if (modifycode == INIT_EXPR)
5027 if (TREE_CODE (rhs) == CONSTRUCTOR)
5029 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5030 /* Call convert to generate an error; see PR 11063. */
5031 rhs = convert (lhstype, rhs);
5032 result = build (INIT_EXPR, lhstype, lhs, rhs);
5033 TREE_SIDE_EFFECTS (result) = 1;
5036 else if (! IS_AGGR_TYPE (lhstype))
5037 /* Do the default thing. */;
5040 result = build_special_member_call (lhs, complete_ctor_identifier,
5041 build_tree_list (NULL_TREE, rhs),
5042 TYPE_BINFO (lhstype),
5044 if (result == NULL_TREE)
5045 return error_mark_node;
5051 if (TREE_CODE (lhstype) == REFERENCE_TYPE)
5053 lhs = convert_from_reference (lhs);
5054 olhstype = lhstype = TREE_TYPE (lhs);
5056 lhs = require_complete_type (lhs);
5057 if (lhs == error_mark_node)
5058 return error_mark_node;
5060 if (modifycode == NOP_EXPR)
5062 /* `operator=' is not an inheritable operator. */
5063 if (! IS_AGGR_TYPE (lhstype))
5064 /* Do the default thing. */;
5067 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5068 lhs, rhs, make_node (NOP_EXPR));
5069 if (result == NULL_TREE)
5070 return error_mark_node;
5077 /* A binary op has been requested. Combine the old LHS
5078 value with the RHS producing the value we should actually
5079 store into the LHS. */
5081 my_friendly_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE),
5083 lhs = stabilize_reference (lhs);
5084 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5085 if (newrhs == error_mark_node)
5087 error (" in evaluation of `%Q(%#T, %#T)'", modifycode,
5088 TREE_TYPE (lhs), TREE_TYPE (rhs));
5089 return error_mark_node;
5092 /* Now it looks like a plain assignment. */
5093 modifycode = NOP_EXPR;
5095 my_friendly_assert (TREE_CODE (lhstype) != REFERENCE_TYPE, 20011220);
5096 my_friendly_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE,
5100 /* The left-hand side must be an lvalue. */
5101 if (!lvalue_or_else (lhs, "assignment"))
5102 return error_mark_node;
5104 /* Warn about modifying something that is `const'. Don't warn if
5105 this is initialization. */
5106 if (modifycode != INIT_EXPR
5107 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5108 /* Functions are not modifiable, even though they are
5110 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5111 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5112 /* If it's an aggregate and any field is const, then it is
5113 effectively const. */
5114 || (CLASS_TYPE_P (lhstype)
5115 && C_TYPE_FIELDS_READONLY (lhstype))))
5116 readonly_error (lhs, "assignment", 0);
5118 /* If storing into a structure or union member, it has probably been
5119 given type `int'. Compute the type that would go with the actual
5120 amount of storage the member occupies. */
5122 if (TREE_CODE (lhs) == COMPONENT_REF
5123 && (TREE_CODE (lhstype) == INTEGER_TYPE
5124 || TREE_CODE (lhstype) == REAL_TYPE
5125 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5127 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5129 /* If storing in a field that is in actuality a short or narrower
5130 than one, we must store in the field in its actual type. */
5132 if (lhstype != TREE_TYPE (lhs))
5134 /* Avoid warnings converting integral types back into enums for
5136 if (TREE_CODE (lhstype) == INTEGER_TYPE
5137 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5139 if (TREE_SIDE_EFFECTS (lhs))
5140 lhs = stabilize_reference (lhs);
5143 lhs = copy_node (lhs);
5144 TREE_TYPE (lhs) = lhstype;
5148 /* Convert new value to destination type. */
5150 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5154 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5155 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5157 error ("incompatible types in assignment of `%T' to `%T'",
5158 TREE_TYPE (rhs), lhstype);
5159 return error_mark_node;
5162 /* Allow array assignment in compiler-generated code. */
5163 if (! DECL_ARTIFICIAL (current_function_decl))
5164 pedwarn ("ISO C++ forbids assignment of arrays");
5166 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5167 ? 1 + (modifycode != INIT_EXPR): 0;
5168 return build_vec_init (lhs, NULL_TREE, newrhs, from_array);
5171 if (modifycode == INIT_EXPR)
5172 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5173 "initialization", NULL_TREE, 0);
5176 /* Avoid warnings on enum bit fields. */
5177 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5178 && TREE_CODE (lhstype) == INTEGER_TYPE)
5180 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5182 newrhs = convert_force (lhstype, newrhs, 0);
5185 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5187 if (TREE_CODE (newrhs) == CALL_EXPR
5188 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5189 newrhs = build_cplus_new (lhstype, newrhs);
5191 /* Can't initialize directly from a TARGET_EXPR, since that would
5192 cause the lhs to be constructed twice, and possibly result in
5193 accidental self-initialization. So we force the TARGET_EXPR to be
5194 expanded without a target. */
5195 if (TREE_CODE (newrhs) == TARGET_EXPR)
5196 newrhs = build (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5197 TREE_OPERAND (newrhs, 0));
5200 if (newrhs == error_mark_node)
5201 return error_mark_node;
5203 result = build (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5204 lhstype, lhs, newrhs);
5206 TREE_SIDE_EFFECTS (result) = 1;
5208 /* If we got the LHS in a different type for storing in,
5209 convert the result back to the nominal type of LHS
5210 so that the value we return always has the same type
5211 as the LHS argument. */
5213 if (olhstype == TREE_TYPE (result))
5217 result = build (COMPOUND_EXPR, olhstype, result, olhs);
5218 TREE_NO_UNUSED_WARNING (result) = 1;
5221 return convert_for_assignment (olhstype, result, "assignment",
5226 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5228 if (processing_template_decl)
5229 return build_min_nt (MODOP_EXPR, lhs,
5230 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5232 if (modifycode != NOP_EXPR)
5234 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5235 make_node (modifycode));
5239 return build_modify_expr (lhs, modifycode, rhs);
5243 /* Get difference in deltas for different pointer to member function
5244 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5245 the conversion is invalid, the constant is zero. If FORCE is true,
5246 then allow reverse conversions as well.
5248 Note that the naming of FROM and TO is kind of backwards; the return
5249 value is what we add to a TO in order to get a FROM. They are named
5250 this way because we call this function to find out how to convert from
5251 a pointer to member of FROM to a pointer to member of TO. */
5254 get_delta_difference (tree from, tree to, int force)
5260 binfo = lookup_base (to, from, ba_check, &kind);
5261 if (kind == bk_inaccessible || kind == bk_ambig)
5263 error (" in pointer to member function conversion");
5270 error_not_base_type (from, to);
5271 error (" in pointer to member conversion");
5274 binfo = lookup_base (from, to, ba_check, &kind);
5277 virt_binfo = binfo_from_vbase (binfo);
5280 /* This is a reinterpret cast, we choose to do nothing. */
5281 warning ("pointer to member cast via virtual base `%T'",
5282 BINFO_TYPE (virt_binfo));
5285 return convert_to_integer (ptrdiff_type_node,
5286 size_diffop (size_zero_node,
5287 BINFO_OFFSET (binfo)));
5290 virt_binfo = binfo_from_vbase (binfo);
5292 return convert_to_integer (ptrdiff_type_node, BINFO_OFFSET (binfo));
5294 /* This is a reinterpret cast, we choose to do nothing. */
5296 warning ("pointer to member cast via virtual base `%T'",
5297 BINFO_TYPE (virt_binfo));
5299 error ("pointer to member conversion via virtual base `%T'",
5300 BINFO_TYPE (virt_binfo));
5303 return convert_to_integer(ptrdiff_type_node, integer_zero_node);
5306 /* Return a constructor for the pointer-to-member-function TYPE using
5307 the other components as specified. */
5310 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5316 /* Pull the FIELD_DECLs out of the type. */
5317 pfn_field = TYPE_FIELDS (type);
5318 delta_field = TREE_CHAIN (pfn_field);
5320 /* Make sure DELTA has the type we want. */
5321 delta = convert_and_check (delta_type_node, delta);
5323 /* Finish creating the initializer. */
5324 u = tree_cons (pfn_field, pfn,
5325 build_tree_list (delta_field, delta));
5326 u = build_constructor (type, u);
5327 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) && TREE_CONSTANT (delta);
5328 TREE_STATIC (u) = (TREE_CONSTANT (u)
5329 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5331 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5336 /* Build a constructor for a pointer to member function. It can be
5337 used to initialize global variables, local variable, or used
5338 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5341 If FORCE is nonzero, then force this conversion, even if
5342 we would rather not do it. Usually set when using an explicit
5345 Return error_mark_node, if something goes wrong. */
5348 build_ptrmemfunc (tree type, tree pfn, int force)
5354 if (error_operand_p (pfn))
5355 return error_mark_node;
5357 pfn_type = TREE_TYPE (pfn);
5358 to_type = build_ptrmemfunc_type (type);
5360 /* Handle multiple conversions of pointer to member functions. */
5361 if (TYPE_PTRMEMFUNC_P (pfn_type))
5363 tree delta = NULL_TREE;
5364 tree npfn = NULL_TREE;
5368 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn))
5369 error ("invalid conversion to type `%T' from type `%T'",
5372 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5373 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5376 /* We don't have to do any conversion to convert a
5377 pointer-to-member to its own type. But, we don't want to
5378 just return a PTRMEM_CST if there's an explicit cast; that
5379 cast should make the expression an invalid template argument. */
5380 if (TREE_CODE (pfn) != PTRMEM_CST)
5382 if (same_type_p (to_type, pfn_type))
5384 else if (integer_zerop (n))
5385 return build_reinterpret_cast (to_type, pfn);
5388 if (TREE_SIDE_EFFECTS (pfn))
5389 pfn = save_expr (pfn);
5391 /* Obtain the function pointer and the current DELTA. */
5392 if (TREE_CODE (pfn) == PTRMEM_CST)
5393 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5396 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5397 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5400 /* Just adjust the DELTA field. */
5401 my_friendly_assert (TREE_TYPE (delta) == ptrdiff_type_node, 20030727);
5402 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5403 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5404 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5405 return build_ptrmemfunc1 (to_type, delta, npfn);
5408 /* Handle null pointer to member function conversions. */
5409 if (integer_zerop (pfn))
5411 pfn = build_c_cast (type, integer_zero_node);
5412 return build_ptrmemfunc1 (to_type,
5417 if (type_unknown_p (pfn))
5418 return instantiate_type (type, pfn, tf_error | tf_warning);
5420 fn = TREE_OPERAND (pfn, 0);
5421 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5422 return make_ptrmem_cst (to_type, fn);
5425 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5428 ??? There is no consistency as to the types returned for the above
5429 values. Some code acts as if it were a sizetype and some as if it were
5430 integer_type_node. */
5433 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5435 tree type = TREE_TYPE (cst);
5436 tree fn = PTRMEM_CST_MEMBER (cst);
5437 tree ptr_class, fn_class;
5439 my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 0);
5441 /* The class that the function belongs to. */
5442 fn_class = DECL_CONTEXT (fn);
5444 /* The class that we're creating a pointer to member of. */
5445 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5447 /* First, calculate the adjustment to the function's class. */
5448 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0);
5450 if (!DECL_VIRTUAL_P (fn))
5451 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5454 /* If we're dealing with a virtual function, we have to adjust 'this'
5455 again, to point to the base which provides the vtable entry for
5456 fn; the call will do the opposite adjustment. */
5457 tree orig_class = DECL_CONTEXT (fn);
5458 tree binfo = binfo_or_else (orig_class, fn_class);
5459 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5460 *delta, BINFO_OFFSET (binfo)));
5462 /* We set PFN to the vtable offset at which the function can be
5463 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5464 case delta is shifted left, and then incremented). */
5465 *pfn = DECL_VINDEX (fn);
5466 *pfn = fold (build (MULT_EXPR, integer_type_node, *pfn,
5467 TYPE_SIZE_UNIT (vtable_entry_type)));
5469 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5471 case ptrmemfunc_vbit_in_pfn:
5472 *pfn = fold (build (PLUS_EXPR, integer_type_node, *pfn,
5476 case ptrmemfunc_vbit_in_delta:
5477 *delta = fold (build (LSHIFT_EXPR, TREE_TYPE (*delta),
5478 *delta, integer_one_node));
5479 *delta = fold (build (PLUS_EXPR, TREE_TYPE (*delta),
5480 *delta, integer_one_node));
5487 *pfn = fold (build1 (NOP_EXPR, TYPE_PTRMEMFUNC_FN_TYPE (type),
5492 /* Return an expression for PFN from the pointer-to-member function
5496 pfn_from_ptrmemfunc (tree t)
5498 if (TREE_CODE (t) == PTRMEM_CST)
5503 expand_ptrmemfunc_cst (t, &delta, &pfn);
5508 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5511 /* Expression EXPR is about to be implicitly converted to TYPE. Warn
5512 if this is a potentially dangerous thing to do. Returns a possibly
5516 dubious_conversion_warnings (tree type, tree expr,
5517 const char *errtype, tree fndecl, int parmnum)
5519 type = non_reference (type);
5521 /* Issue warnings about peculiar, but valid, uses of NULL. */
5522 if (ARITHMETIC_TYPE_P (type) && expr == null_node)
5525 warning ("passing NULL used for non-pointer %s %P of `%D'",
5526 errtype, parmnum, fndecl);
5528 warning ("%s to non-pointer type `%T' from NULL", errtype, type);
5531 /* Warn about assigning a floating-point type to an integer type. */
5532 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
5533 && TREE_CODE (type) == INTEGER_TYPE)
5536 warning ("passing `%T' for %s %P of `%D'",
5537 TREE_TYPE (expr), errtype, parmnum, fndecl);
5539 warning ("%s to `%T' from `%T'", errtype, type, TREE_TYPE (expr));
5541 /* And warn about assigning a negative value to an unsigned
5543 else if (TREE_UNSIGNED (type) && TREE_CODE (type) != BOOLEAN_TYPE)
5545 if (TREE_CODE (expr) == INTEGER_CST
5546 && TREE_NEGATED_INT (expr))
5549 warning ("passing negative value `%E' for %s %P of `%D'",
5550 expr, errtype, parmnum, fndecl);
5552 warning ("%s of negative value `%E' to `%T'",
5553 errtype, expr, type);
5556 overflow_warning (expr);
5558 if (TREE_CONSTANT (expr))
5564 /* Convert value RHS to type TYPE as preparation for an assignment to
5565 an lvalue of type TYPE. ERRTYPE is a string to use in error
5566 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5567 are doing the conversion in order to pass the PARMNUMth argument of
5571 convert_for_assignment (tree type, tree rhs,
5572 const char *errtype, tree fndecl, int parmnum)
5575 enum tree_code coder;
5577 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5578 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5579 rhs = TREE_OPERAND (rhs, 0);
5581 rhstype = TREE_TYPE (rhs);
5582 coder = TREE_CODE (rhstype);
5584 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
5585 && ((*targetm.vector_opaque_p) (type)
5586 || (*targetm.vector_opaque_p) (rhstype)))
5587 return convert (type, rhs);
5589 if (rhs == error_mark_node || rhstype == error_mark_node)
5590 return error_mark_node;
5591 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
5592 return error_mark_node;
5594 /* The RHS of an assignment cannot have void type. */
5595 if (coder == VOID_TYPE)
5597 error ("void value not ignored as it ought to be");
5598 return error_mark_node;
5601 /* Simplify the RHS if possible. */
5602 if (TREE_CODE (rhs) == CONST_DECL)
5603 rhs = DECL_INITIAL (rhs);
5605 /* We do not use decl_constant_value here because of this case:
5607 const char* const s = "s";
5609 The conversion rules for a string literal are more lax than for a
5610 variable; in particular, a string literal can be converted to a
5611 "char *" but the variable "s" cannot be converted in the same
5612 way. If the conversion is allowed, the optimization should be
5613 performed while creating the converted expression. */
5617 The expression is implicitly converted (clause _conv_) to the
5618 cv-unqualified type of the left operand.
5620 We allow bad conversions here because by the time we get to this point
5621 we are committed to doing the conversion. If we end up doing a bad
5622 conversion, convert_like will complain. */
5623 if (!can_convert_arg_bad (type, rhstype, rhs))
5625 /* When -Wno-pmf-conversions is use, we just silently allow
5626 conversions from pointers-to-members to plain pointers. If
5627 the conversion doesn't work, cp_convert will complain. */
5629 && TYPE_PTR_P (type)
5630 && TYPE_PTRMEMFUNC_P (rhstype))
5631 rhs = cp_convert (strip_top_quals (type), rhs);
5634 /* If the right-hand side has unknown type, then it is an
5635 overloaded function. Call instantiate_type to get error
5637 if (rhstype == unknown_type_node)
5638 instantiate_type (type, rhs, tf_error | tf_warning);
5640 error ("cannot convert `%T' to `%T' for argument `%P' to `%D'",
5641 rhstype, type, parmnum, fndecl);
5643 error ("cannot convert `%T' to `%T' in %s", rhstype, type,
5645 return error_mark_node;
5648 return perform_implicit_conversion (strip_top_quals (type), rhs);
5651 /* Convert RHS to be of type TYPE.
5652 If EXP is nonzero, it is the target of the initialization.
5653 ERRTYPE is a string to use in error messages.
5655 Two major differences between the behavior of
5656 `convert_for_assignment' and `convert_for_initialization'
5657 are that references are bashed in the former, while
5658 copied in the latter, and aggregates are assigned in
5659 the former (operator=) while initialized in the
5662 If using constructor make sure no conversion operator exists, if one does
5663 exist, an ambiguity exists.
5665 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
5668 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
5669 const char *errtype, tree fndecl, int parmnum)
5671 enum tree_code codel = TREE_CODE (type);
5673 enum tree_code coder;
5675 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5676 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
5677 if (TREE_CODE (rhs) == NOP_EXPR
5678 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
5679 && codel != REFERENCE_TYPE)
5680 rhs = TREE_OPERAND (rhs, 0);
5682 if (rhs == error_mark_node
5683 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
5684 return error_mark_node;
5686 if (TREE_CODE (TREE_TYPE (rhs)) == REFERENCE_TYPE)
5687 rhs = convert_from_reference (rhs);
5689 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
5690 && TREE_CODE (type) != ARRAY_TYPE
5691 && (TREE_CODE (type) != REFERENCE_TYPE
5692 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
5693 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
5694 && (TREE_CODE (type) != REFERENCE_TYPE
5695 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
5696 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
5697 rhs = decay_conversion (rhs);
5699 rhstype = TREE_TYPE (rhs);
5700 coder = TREE_CODE (rhstype);
5702 if (coder == ERROR_MARK)
5703 return error_mark_node;
5705 /* We accept references to incomplete types, so we can
5706 return here before checking if RHS is of complete type. */
5708 if (codel == REFERENCE_TYPE)
5710 /* This should eventually happen in convert_arguments. */
5711 int savew = 0, savee = 0;
5714 savew = warningcount, savee = errorcount;
5715 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
5719 if (warningcount > savew)
5720 cp_warning_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5721 else if (errorcount > savee)
5722 cp_error_at ("in passing argument %P of `%+D'", parmnum, fndecl);
5728 exp = require_complete_type (exp);
5729 if (exp == error_mark_node)
5730 return error_mark_node;
5732 rhstype = non_reference (rhstype);
5734 type = complete_type (type);
5736 if (IS_AGGR_TYPE (type))
5737 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
5739 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
5742 /* Expand an ASM statement with operands, handling output operands
5743 that are not variables or INDIRECT_REFS by transforming such
5744 cases into cases that expand_asm_operands can handle.
5746 Arguments are same as for expand_asm_operands.
5748 We don't do default conversions on all inputs, because it can screw
5749 up operands that are expected to be in memory. */
5752 c_expand_asm_operands (tree string, tree outputs, tree inputs, tree clobbers,
5753 int vol, location_t locus)
5755 int noutputs = list_length (outputs);
5757 /* o[I] is the place that output number I should be written. */
5758 tree *o = alloca (noutputs * sizeof (tree));
5761 /* Record the contents of OUTPUTS before it is modified. */
5762 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5763 o[i] = TREE_VALUE (tail);
5765 /* Generate the ASM_OPERANDS insn;
5766 store into the TREE_VALUEs of OUTPUTS some trees for
5767 where the values were actually stored. */
5768 expand_asm_operands (string, outputs, inputs, clobbers, vol, locus);
5770 /* Copy all the intermediate outputs into the specified outputs. */
5771 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
5773 if (o[i] != TREE_VALUE (tail))
5775 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)),
5776 const0_rtx, VOIDmode, EXPAND_NORMAL);
5779 /* Restore the original value so that it's correct the next
5780 time we expand this function. */
5781 TREE_VALUE (tail) = o[i];
5783 /* Detect modification of read-only values.
5784 (Otherwise done by build_modify_expr.) */
5787 tree type = TREE_TYPE (o[i]);
5788 if (type != error_mark_node
5789 && (CP_TYPE_CONST_P (type)
5790 || (CLASS_TYPE_P (type) && C_TYPE_FIELDS_READONLY (type))))
5791 readonly_error (o[i], "modification by `asm'", 1);
5795 /* Those MODIFY_EXPRs could do autoincrements. */
5799 /* If RETVAL is the address of, or a reference to, a local variable or
5800 temporary give an appropriate warning. */
5803 maybe_warn_about_returning_address_of_local (tree retval)
5805 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
5806 tree whats_returned = retval;
5810 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
5811 whats_returned = TREE_OPERAND (whats_returned, 1);
5812 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
5813 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
5814 || TREE_CODE (whats_returned) == NOP_EXPR)
5815 whats_returned = TREE_OPERAND (whats_returned, 0);
5820 if (TREE_CODE (whats_returned) != ADDR_EXPR)
5822 whats_returned = TREE_OPERAND (whats_returned, 0);
5824 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5826 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
5827 || TREE_CODE (whats_returned) == TARGET_EXPR)
5829 warning ("returning reference to temporary");
5832 if (TREE_CODE (whats_returned) == VAR_DECL
5833 && DECL_NAME (whats_returned)
5834 && TEMP_NAME_P (DECL_NAME (whats_returned)))
5836 warning ("reference to non-lvalue returned");
5841 if (DECL_P (whats_returned)
5842 && DECL_NAME (whats_returned)
5843 && DECL_FUNCTION_SCOPE_P (whats_returned)
5844 && !(TREE_STATIC (whats_returned)
5845 || TREE_PUBLIC (whats_returned)))
5847 if (TREE_CODE (valtype) == REFERENCE_TYPE)
5848 cp_warning_at ("reference to local variable `%D' returned",
5851 cp_warning_at ("address of local variable `%D' returned",
5857 /* Check that returning RETVAL from the current function is valid.
5858 Return an expression explicitly showing all conversions required to
5859 change RETVAL into the function return type, and to assign it to
5860 the DECL_RESULT for the function. */
5863 check_return_expr (tree retval)
5866 /* The type actually returned by the function, after any
5869 int fn_returns_value_p;
5871 /* A `volatile' function is one that isn't supposed to return, ever.
5872 (This is a G++ extension, used to get better code for functions
5873 that call the `volatile' function.) */
5874 if (TREE_THIS_VOLATILE (current_function_decl))
5875 warning ("function declared `noreturn' has a `return' statement");
5877 /* Check for various simple errors. */
5878 if (DECL_DESTRUCTOR_P (current_function_decl))
5881 error ("returning a value from a destructor");
5884 else if (DECL_CONSTRUCTOR_P (current_function_decl))
5886 if (in_function_try_handler)
5887 /* If a return statement appears in a handler of the
5888 function-try-block of a constructor, the program is ill-formed. */
5889 error ("cannot return from a handler of a function-try-block of a constructor");
5891 /* You can't return a value from a constructor. */
5892 error ("returning a value from a constructor");
5896 if (processing_template_decl)
5898 current_function_returns_value = 1;
5902 /* When no explicit return-value is given in a function with a named
5903 return value, the named return value is used. */
5904 result = DECL_RESULT (current_function_decl);
5905 valtype = TREE_TYPE (result);
5906 my_friendly_assert (valtype != NULL_TREE, 19990924);
5907 fn_returns_value_p = !VOID_TYPE_P (valtype);
5908 if (!retval && DECL_NAME (result) && fn_returns_value_p)
5911 /* Check for a return statement with no return value in a function
5912 that's supposed to return a value. */
5913 if (!retval && fn_returns_value_p)
5915 pedwarn ("return-statement with no value, in function returning '%T'",
5917 /* Clear this, so finish_function won't say that we reach the
5918 end of a non-void function (which we don't, we gave a
5920 current_function_returns_null = 0;
5922 /* Check for a return statement with a value in a function that
5923 isn't supposed to return a value. */
5924 else if (retval && !fn_returns_value_p)
5926 if (VOID_TYPE_P (TREE_TYPE (retval)))
5927 /* You can return a `void' value from a function of `void'
5928 type. In that case, we have to evaluate the expression for
5929 its side-effects. */
5930 finish_expr_stmt (retval);
5932 pedwarn ("return-statement with a value, in function "
5933 "returning 'void'");
5935 current_function_returns_null = 1;
5937 /* There's really no value to return, after all. */
5941 /* Remember that this function can sometimes return without a
5943 current_function_returns_null = 1;
5945 /* Remember that this function did return a value. */
5946 current_function_returns_value = 1;
5948 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
5949 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
5950 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
5951 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
5953 && null_ptr_cst_p (retval))
5954 warning ("`operator new' must not return NULL unless it is declared `throw()' (or -fcheck-new is in effect)");
5956 /* Effective C++ rule 15. See also start_function. */
5958 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR)
5959 && retval != current_class_ref)
5960 warning ("`operator=' should return a reference to `*this'");
5962 /* The fabled Named Return Value optimization, as per [class.copy]/15:
5964 [...] For a function with a class return type, if the expression
5965 in the return statement is the name of a local object, and the cv-
5966 unqualified type of the local object is the same as the function
5967 return type, an implementation is permitted to omit creating the tem-
5968 porary object to hold the function return value [...]
5970 So, if this is a value-returning function that always returns the same
5971 local variable, remember it.
5973 It might be nice to be more flexible, and choose the first suitable
5974 variable even if the function sometimes returns something else, but
5975 then we run the risk of clobbering the variable we chose if the other
5976 returned expression uses the chosen variable somehow. And people expect
5977 this restriction, anyway. (jason 2000-11-19)
5979 See finish_function, cxx_expand_function_start, and
5980 cp_copy_res_decl_for_inlining for other pieces of this
5983 if (fn_returns_value_p && flag_elide_constructors)
5985 if (retval != NULL_TREE
5986 && (current_function_return_value == NULL_TREE
5987 || current_function_return_value == retval)
5988 && TREE_CODE (retval) == VAR_DECL
5989 && DECL_CONTEXT (retval) == current_function_decl
5990 && ! TREE_STATIC (retval)
5991 && (DECL_ALIGN (retval)
5992 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
5993 && same_type_p ((TYPE_MAIN_VARIANT
5994 (TREE_TYPE (retval))),
5996 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
5997 current_function_return_value = retval;
5999 current_function_return_value = error_mark_node;
6002 /* We don't need to do any conversions when there's nothing being
6004 if (!retval || retval == error_mark_node)
6007 /* Do any required conversions. */
6008 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6009 /* No conversions are required. */
6013 /* The type the function is declared to return. */
6014 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6016 /* First convert the value to the function's return type, then
6017 to the type of return value's location to handle the
6018 case that functype is smaller than the valtype. */
6019 retval = convert_for_initialization
6020 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6021 "return", NULL_TREE, 0);
6022 retval = convert (valtype, retval);
6024 /* If the conversion failed, treat this just like `return;'. */
6025 if (retval == error_mark_node)
6027 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6028 else if (! current_function_returns_struct
6029 && TREE_CODE (retval) == TARGET_EXPR
6030 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6031 retval = build (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6032 TREE_OPERAND (retval, 0));
6034 maybe_warn_about_returning_address_of_local (retval);
6037 /* Actually copy the value returned into the appropriate location. */
6038 if (retval && retval != result)
6039 retval = build (INIT_EXPR, TREE_TYPE (result), result, retval);
6045 /* Returns nonzero if the pointer-type FROM can be converted to the
6046 pointer-type TO via a qualification conversion. If CONSTP is -1,
6047 then we return nonzero if the pointers are similar, and the
6048 cv-qualification signature of FROM is a proper subset of that of TO.
6050 If CONSTP is positive, then all outer pointers have been
6054 comp_ptr_ttypes_real (tree to, tree from, int constp)
6056 bool to_more_cv_qualified = false;
6058 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6060 if (TREE_CODE (to) != TREE_CODE (from))
6063 if (TREE_CODE (from) == OFFSET_TYPE
6064 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6065 TYPE_OFFSET_BASETYPE (to)))
6068 /* Const and volatile mean something different for function types,
6069 so the usual checks are not appropriate. */
6070 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6072 if (!at_least_as_qualified_p (to, from))
6075 if (!at_least_as_qualified_p (from, to))
6079 to_more_cv_qualified = true;
6083 constp &= TYPE_READONLY (to);
6086 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6087 return ((constp >= 0 || to_more_cv_qualified)
6088 && same_type_ignoring_top_level_qualifiers_p (to, from));
6092 /* When comparing, say, char ** to char const **, this function takes
6093 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6094 types to this function. */
6097 comp_ptr_ttypes (tree to, tree from)
6099 return comp_ptr_ttypes_real (to, from, 1);
6102 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6103 type or inheritance-related types, regardless of cv-quals. */
6106 ptr_reasonably_similar (tree to, tree from)
6108 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6110 /* Any target type is similar enough to void. */
6111 if (TREE_CODE (to) == VOID_TYPE
6112 || TREE_CODE (from) == VOID_TYPE)
6115 if (TREE_CODE (to) != TREE_CODE (from))
6118 if (TREE_CODE (from) == OFFSET_TYPE
6119 && comptypes (TYPE_OFFSET_BASETYPE (to),
6120 TYPE_OFFSET_BASETYPE (from),
6121 COMPARE_BASE | COMPARE_DERIVED))
6124 if (TREE_CODE (to) == INTEGER_TYPE
6125 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6128 if (TREE_CODE (to) == FUNCTION_TYPE)
6131 if (TREE_CODE (to) != POINTER_TYPE)
6133 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6134 COMPARE_BASE | COMPARE_DERIVED);
6138 /* Like comp_ptr_ttypes, for const_cast. */
6141 comp_ptr_ttypes_const (tree to, tree from)
6143 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6145 if (TREE_CODE (to) != TREE_CODE (from))
6148 if (TREE_CODE (from) == OFFSET_TYPE
6149 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6150 TYPE_OFFSET_BASETYPE (to)))
6153 if (TREE_CODE (to) != POINTER_TYPE)
6154 return same_type_ignoring_top_level_qualifiers_p (to, from);
6158 /* Returns the type qualifiers for this type, including the qualifiers on the
6159 elements for an array type. */
6162 cp_type_quals (tree type)
6164 type = strip_array_types (type);
6165 if (type == error_mark_node)
6166 return TYPE_UNQUALIFIED;
6167 return TYPE_QUALS (type);
6170 /* Returns nonzero if the TYPE contains a mutable member. */
6173 cp_has_mutable_p (tree type)
6175 type = strip_array_types (type);
6177 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6180 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6181 exemplar types such that casting T1 to T2 is casting away castness
6182 if and only if there is no implicit conversion from T1 to T2. */
6185 casts_away_constness_r (tree *t1, tree *t2)
6190 /* [expr.const.cast]
6192 For multi-level pointer to members and multi-level mixed pointers
6193 and pointers to members (conv.qual), the "member" aspect of a
6194 pointer to member level is ignored when determining if a const
6195 cv-qualifier has been cast away. */
6196 if (TYPE_PTRMEM_P (*t1))
6197 *t1 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t1));
6198 if (TYPE_PTRMEM_P (*t2))
6199 *t2 = build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (*t2));
6201 /* [expr.const.cast]
6203 For two pointer types:
6205 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6206 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6209 casting from X1 to X2 casts away constness if, for a non-pointer
6210 type T there does not exist an implicit conversion (clause
6213 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6217 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6219 if (TREE_CODE (*t1) != POINTER_TYPE
6220 || TREE_CODE (*t2) != POINTER_TYPE)
6222 *t1 = cp_build_qualified_type (void_type_node,
6223 cp_type_quals (*t1));
6224 *t2 = cp_build_qualified_type (void_type_node,
6225 cp_type_quals (*t2));
6229 quals1 = cp_type_quals (*t1);
6230 quals2 = cp_type_quals (*t2);
6231 *t1 = TREE_TYPE (*t1);
6232 *t2 = TREE_TYPE (*t2);
6233 casts_away_constness_r (t1, t2);
6234 *t1 = build_pointer_type (*t1);
6235 *t2 = build_pointer_type (*t2);
6236 *t1 = cp_build_qualified_type (*t1, quals1);
6237 *t2 = cp_build_qualified_type (*t2, quals2);
6240 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6244 casts_away_constness (tree t1, tree t2)
6246 if (TREE_CODE (t2) == REFERENCE_TYPE)
6248 /* [expr.const.cast]
6250 Casting from an lvalue of type T1 to an lvalue of type T2
6251 using a reference cast casts away constness if a cast from an
6252 rvalue of type "pointer to T1" to the type "pointer to T2"
6253 casts away constness. */
6254 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6255 return casts_away_constness (build_pointer_type (t1),
6256 build_pointer_type (TREE_TYPE (t2)));
6259 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6260 /* [expr.const.cast]
6262 Casting from an rvalue of type "pointer to data member of X
6263 of type T1" to the type "pointer to data member of Y of type
6264 T2" casts away constness if a cast from an rvalue of type
6265 "pointer to T1" to the type "pointer to T2" casts away
6267 return casts_away_constness
6268 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6269 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6271 /* Casting away constness is only something that makes sense for
6272 pointer or reference types. */
6273 if (TREE_CODE (t1) != POINTER_TYPE
6274 || TREE_CODE (t2) != POINTER_TYPE)
6277 /* Top-level qualifiers don't matter. */
6278 t1 = TYPE_MAIN_VARIANT (t1);
6279 t2 = TYPE_MAIN_VARIANT (t2);
6280 casts_away_constness_r (&t1, &t2);
6281 if (!can_convert (t2, t1))
6287 /* If T is a REFERENCE_TYPE return the type to which T refers.
6288 Otherwise, return T itself. */
6291 non_reference (tree t)
6293 if (TREE_CODE (t) == REFERENCE_TYPE)